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Acidification of liquid egg prior to drying did not improve subsequent storage life, although pH measurements showed that powder from untreated egg became acid more rapidly during storage. Reduction in the moisture content (total volatiles) from 4.7 to 3.0% doubled, and reduction from 4.7 to 1.7% tripled, the storage life of dried whole egg powder as assessed by fluorescence tests. The maximum storage life predicted for the low moisture powder by this test was only 36 wk. at 27 °C. and 5 wk. at 38 °C. Palatability tests suggested that the product was somewhat less perishable, as a powder of 1.7% moisture was considered fit for use as an egg dish after 64 wk. at 27 °C. Gas-packing low moisture powders in an atmosphere of carbon dioxide appeared to be slightly more effective as a means of retaining palatability than packing in an atmosphere of air or nitrogen, but was particularly effective in preventing loss of solubility (assessed by potassium chloride values) during storage.

Gliadin prepared by several different methods had the same nitrogen content and distribution. The critical peptization temperature (C.P.T.) in 60% alcohol and viscosity in 30% urea-buffer solutions, however, showed considerable variation, preparations of high C.P.T. (low solubility) being more viscous. This variation in the physical properties is explained by fractionation or denaturation incidental to the method of preparation.Gluten precipitated from 30% urea solutions at salt concentrations varying from 0.1 to 0.5 of saturation, yielded fractions that varied continuously in their gliadin and glutenin content, as judged from their percentage of arginine nitrogen.Gluten dispersed in buffered 30% urea solutions showed no change in viscosity during 101 hr. after the gluten was completely dispersed. A variation of hydrogen ion concentration between pH 6.0 and 6.95 had little effect on its viscosity. Heating at 70 °C. caused a marked decrease in the viscosity of this dispersion during the first hour. When gliadin dispersions are heated as above only samples having a high initial viscosity and C.P.T. become less viscous. Heating gliadin of natural moisture content (12 to 14%) at 70 °C. for varying periods of time did not change significantly its subsequent C.P.T. and viscosity in 60% alcohol. More severe heat treatments at higher moisture contents rendered the gliadin insoluble in 60% alcohol. Dilute alcoholic extracts of heated flours contained less protein than those of unheated controls. However, the C.P.T. of the former was lower than that of the latter. It is concluded from these experiments that when the gluten proteins are subjected to elevated temperatures, the glutenin fraction is first affected, next the gliadin fractions of low solubility, and finally, under severe conditions, all of the gliadin is denatured.

Of 15 chemicals applied to perennial weeds over the same range of dosages, only five appear to possess a useful toxicity as judged by the number of living plants 12 months after treatment. The effective chemicals can be classified into three groups according to their toxicity, (i) sodium chlorate; (ii) barium chlorate and arsenic pentoxide; and (iii) ammonium thiocyanate and sodium arsenite. The relative toxicity of these three groups of chemicals, judged from the certainly lethal dosage, appears to fall in the proportions of 1:1.5:> 2.

Measurements of the colour and colour stability of Wiltshire bacon, cured in a factory known to produce a generally satisfactory product, showed that there were small but significant differences in these properties from time to time, but there was no definite evidence to indicate that these differences could be attributed to systematic seasonal effects.

Highly significant differences in chloride content were observed at different positions across the ham of Wiltshire sides, the portion next to the tank pickle during cure usually containing the most chloride. Of the various factors studied, the number of injections used for pumping a side, and the age from cure, were the only ones found to affect the chloride distribution. Greater uniformity was obtained by increasing the number of injections, and with increasing age from cure. Within the range used in practice for curing Wiltshire sides, the chloride content of the pickles or the number of days in cure was not related to the chloride distribution. An equation is given relating the uniformity of chloride distribution to the number of injections used per side in pumping, and the number of days from the end of cure. This equation indicates that, on the average, the variations in the chloride content within the ham of a Wiltshire side will be reduced to the same magnitude as the variations between sides cured in the same plant, after holding at 1.1 °C. for periods of about 12, 26, and 30 days, for sides receiving 27, 8, and 0 injections, respectively.

Some 300 samples of hard red spring wheat, 50 of amber durum wheat and 75 each of oats and barley, covering the entire moisture range of commercial importance, were employed in the comparisons. Provision was made for statistical estimation of sampling errors, errors of method and errors of observation. A two-stage drying procedure was employed for the vacuum oven determinations which were taken as the reference standard. Sampling errors, average difference between identical ovens and errors due to daily fluctuations were all larger than the standard deviation of duplicates ("experimental error"), the sampling error being the largest.A comparison of the Hobart and Wiley grinders shows the latter to be superior for preparing wheat for the 130 °C. air oven determination. The air oven consistently underestimates the moisture content of all the grains tested, as compared with the vacuum oven, the deficit increasing with the actual moisture content. This systematic bias may be eliminated by means of a linear correction equation. After allowing for the observed sampling errors and errors of the vacuum oven determination, the net standard error of prediction with the air oven using a Wiley mill is, with hard red spring wheat 0.24%, with amber durum wheat 0.12%, with barley 0.20% and with oats 0.20% moisture.The Brown-Duvel method also underestimates the moisture content, this deficit also increasing with the actual moisture content in the case of spring and amber durum wheat. After applying a correction equation to eliminate the systematic bias, the net standard error of prediction of moisture by this method was found to be: with hard red spring wheat 0.16%, with durum wheat 0.09%, with barley 0.12% and with oats 0.13%. The Brown-Duvel method, therefore, when carefully operated makes possible a more consistent estimate of the actual moisture content, as determined by the vacuum oven, than does the 130 °C. air oven method. As with the vacuum oven, both the 130 °C. air oven and the Brown-Duvel appear to be subject to slight variations affecting all the determinations made on any particular day.

Temperatures below −17.7 °C. (0° F.) and moisture resistant, preferably impermeable, wrappings are desirable for the retention of colour of pork during storage. Although pork thawed in air or water was lighter in colour than that thawed in brine or pickle, the difference was markedly reduced after curing and maturation. Nevertheless, the colour of the final product was significantly correlated with that of the pork after thawing. Samples stored under conditions that retain the original colour, or subsequently thawed by procedures that produce light colours, are the least stable after defrosting. On the average there was comparatively little difference between the colour of exposed and internal samples, although the former were more variable. Pale-drying yielded samples with a lighter internal colour than did the usual smoking procedure.

Measurements made under a series of imposed conditions of heat load, dunnage spacing, and air flow were in agreement with previous work in this laboratory in demonstrating (a) the occurrence of appreciable permanent temperature gradients in material, whether exothermic or not, stacked in an air-cooled storage room, and (b) the possibility of markedly reducing these gradients by effective channelling of air through the stack. With end-to-end circulation, blocking of voids in the room was the most important single factor in minimizing intra-stack temperature differentials under the conditions of these tests. Further improvement was effected by the provision of optimum dunnage and by augmenting the air flow. It is to be inferred that with blocked voids, dunnage should be extended to all external surfaces of the stack. The desirability of uniform transverse and vertical distribution of the circulating air was also evident. Further trials on a larger scale are required to explore the practical implications of these findings.

A photoelectric colour comparator, previously described (Can. J. Research, D, 17: 1-7. 1939) has been improved to permit greater precision and more rapid operation. Measurements on meat indicate that the degree of precision attainable with the new comparator is determined primarily by sampling, rather than instrumental, errors.

A package constructed from moisture resistant material, capable of being ventilated during chilled storage, and sealed to prevent surface drying during frozen storage, is described. Results are presented to demonstrate the ability of this package to maintain the desired humidity conditions. Jacketing a room to separate the cooling coils from the space occupied by the product does not prevent surface drying of boxed goods, presumably because of the absorption of moisture by the boxes. Delays between slaughter and freezing accelerate the development of rancidity in the fat of poultry during subsequent frozen storage, as indicated by the formation of peroxide oxygen. The free fatty acid content is not seriously affected unless the conditions prior to freezing enhance microbial development.

A wet test meter was used to measure the air supplied to a small wind tunnel that could be adjusted to provide up-, down-, or side-draughts for the calibration of a sensitive hot-wire anemometer. The readings on the instrument used were independent of the direction of air flow and the orientation of the instrument at velocities in excess of 10 ft. per min. At lower velocities separate curves were obtained for different instrument orientations and directions of air movement. Air flows as low as 1 ft. per min. can be estimated with useful accuracy provided the direction of air movement is known.

Analysis of Wiltshire bacon produced in Canadian plants showed that different sides varied in their chloride, nitrate, and nitrite contents, the chloride content being the most uniform. Although the observed variations were statistically significant they do not necessarily affect the quality of the product. An analysis of variance showed that differences between the sides from different plants were the main general source of variation in the chloride and nitrate contents, while the differences between sides from the same plant were the main source of variation in nitrite content. This, and other evidence, indicates that the properties of the individual side affect its nitrite content to a considerable extent.The variation in the composition of the pickles used in different plants was significantly greater than the variations within plants, although the chloride content was relatively uniform throughout. Other curing practices, such as the number of injections used for pumping a side and the time in cure, also varied between different plants. Statistical computations showed that the number of injections used for pumping was correlated with the chloride and nitrite content of the sides, while their nitrate content was correlated with the nitrate content of the pump pickle. Although these factors affected the composition of the product with respect to each constituent, the level of the correlation coefficients was rather low. It is therefore concluded that most of the observed variation in the bacon was contributed by other unmeasured factors, or by inherent differences between the carcasses.The analysis of variance showed significant differences between the content of the three constituents at different samplings. The method of sampling, however, did not permit the true effect of ageing to be distinguished precisely from the effect of systematic differences in position, and the observed differences between samplings might possibly have been due entirely to the effect of position.

Dilute sodium hydroxide and dilute acetic acid both hydrolyze gluten even at 0 °C., the reaction constant and temperature coefficient being greatest in dispersions in alkali. The reaction appears to be unimolecular in both reagents although it seems probable that neither of these can effect complete hydrolysis. No appreciable hydrolysis occurred in gluten dispersed in urea or sodium salicylate solutions, even after relatively drastic heat treatment.

Toxicity tests on four annual weeds, Thlaspi arvense L.; Brassica arvensis L. Ktze.; Chenopodium album L.; and Avena fatua L.; showed no definite evidence of a specific susceptibility of a given species to a given substance. The relative resistance of these four weeds to most substances, judging from the certainly lethal dose, was in the order 1:1:2:7. Of the 76 chemicals tested, the following most toxic compounds killed all four species at the dosages employed; selenic and chloric acids, sodium hydroxide, arsenic pentoxide, sodium arsenite, sodium and ammonium chlorate, ammonium thiocyanate, sodium cyanide, zinc chloride, sodium bichromate, sodium selenite, copper nitrate, sodium sulphide, formic acid, gasoline, phenol, creosote, tetralin, sodium benzoate, aniline, benzene and furfural. The residual toxic effect on the soil, three to four weeks after treatment, showed that of the 35 more toxic chemicals tested, only selenic acid and the five chlorates used had any appreciable effect at low and intermediate dosages, while eleven other substances depressed growth following the application of high dosages.

This paper introduces an investigation involving bacterial, chemical, and physical measurements on bacon and pickle from 22 packing plants. The objects were to determine the over-all variation occurring in practice, the general sources of the variation, and the specific effect of certain curing practices. Methods employed for shipping the samples, sampling, and analyses are described.It was found that small samples of curing pickle change slightly in nitrite and bacterial content during shipping periods approaching a week's duration, but that these changes are of negligible importance from a practical standpoint if the pickles are kept at temperatures near the freezing point.

An enclosed system of piping partly filled with liquid ammonia was found to transfer useful quantities of heat to a bunker containing a solid refrigerant (ice), with temperature gradients of 30 to 50° F. without the use of forced circulation. The system could be adapted to reduce spatial temperature variations and provide thermostatic control where solid refrigerants are used, as in railway refrigerator cars. Such arrangements are discussed briefly.

Pork cuts were stored at relative humidities of 83, 87, 92, 96, and 100% and temperatures of − 6.6°, − 12.2°, − 17.7°, and − 23 °C. for 48 weeks. Visual examination revealed various degrees of surface drying under all conditions, and pronounced methaemoglobin formation at − 6.6 °C. Quantitative colour measurements on both the exposed and internal surfaces of the lean, showed that storage temperature was the primary factor affecting the colour. Temperatures of − 18 °C., or lower, are required to prevent these changes. Samples that had suffered the greatest colour change during storage showed the least change during subsequent exposure.Temperature was also the primary factor affecting the development of rancidity in the fat. Both peroxide oxygen and free fatty acid increased significantly with increase in storage temperature, particularly between − 12.2° and − 6.6 °C., but the actual quantities of free fatty acid were small and of little consequence. Storage temperatures of − 18 °C., or lower, are essential if spoilage of pork fat is to be avoided over storage periods of approximately one year's duration.

The bound-water method was modified for use with flour suspensions and provided a simple means for the direct measurement of the approximate hydration of the colloidal constituents in dilute lactic acid. The average hydration of the dry matter in 15% suspensions was in the region of 40 to 50%, the value being slightly higher in washed suspensions. Starch maintained a hydration close to 30%, under all conditions investigated. The prepared proteins, in dilute lactic acid, were hydrated about 85%. The calculated hydration of the proteins as they occurred in the flour was about 100% in unwashed and 200% in washed suspensions.No significant differences were found by this method in the hydration of strong and weak flours, and it is thought that such differences as may exist are too small to be of major importance as factors in baking quality. The experimental results are harmonized with the facts concerning viscosity and the behavior of bread dough by assuming micellar aggregation of the gluten.

A new method has been developed for preparing glutenin, using concentrated urea solution as a dispersion medium. The starch is removed from the dispersion by passing it through a Sharpies supercentrifuge. The glutenin is then removed from the gliadin by precipitation: (a) by adding magnesium sulphate to about 0.17 of saturation; or (b) by adding water until the urea is diluted to about 10% concentration. Alcohol precipitation is unsatisfactory, since the glutenin loses much of its original solubility. Drying, even at room temperature, renders glutenin insoluble in 30% urea solution. Different samples of glutenin isolated by the urea method have similar amide and arginine nitrogen contents. The amount of these constituents is intermediate between the values reported for glutenin isolated from alkali, and that isolated from acid. While urea solutions denature some proteins, they affect glutenin less than dilute alkalies, as judged by the sulphydryl test, and no more than dilute acids. Neutral urea solutions permit a study of the physical properties of glutenin without previous exposure to extremes of hydrogen ion concentration. This method should be applicable to the isolation of glutenins from other seeds.

Simple correlation coefficients computed between several observed properties and constituents of factory-cured Wiltshire bacon showed the following to be associated: nitrate and chloride contents; nitrite and chloride contents; nitrite content and pH; and moisture and chloride contents. The first two of these associations probably arise from the pickle compositions and curing practices followed in the plants. The last two associations suggest a certain degree of dependence between the two properties, i.e., the nitrite content of the meat increases with the pH, and the moisture content decreases as the chloride content increases. When the moisture content of the bacon was expressed on a salt-free basis, the correlation between the moisture and chloride contents was not significant. This indicates that curing practices favouring a high salt content do not result in the removal of more moisture from the sides.

The combustibility of organic matter-sodium chlorate mixtures in various proportions has been tested at different relative humidities. It was found that mixtures containing more than 10% of sodium chlorate are sufficiently combustible to be hazardous at all relative humidities below 75% but are non-hazardous at higher humidities. Data were obtained showing the minimum moisture content required for protecting such mixtures and this information may be used to calculate the approximate amount of any water-absorbing chemical that has to be added to sodium chlorate to render it safe. Admixture of calcium chloride or magnesium chloride with the sodium chlorate renders the mixture safe when these protecting salts form one-half and one-third respectively of the resulting herbicide. Judging from the chlorate content the above sodium chlorate-magnesium chloride mixture would be the most effective "safe" herbicide of those tested, but it would be about only half as toxic as pure sodium chlorate. Several other salts were tested as protecting agents but they were either ineffective or resulted in the decomposition of the chlorate. Combustibility tests were also conducted on barium chlorate- and calcium chlorate-organic matter mixtures. These mixtures are less inflammable than those containing sodium chlorate but are sufficiently combustible to be a fire hazard in districts where the atmospheric humidity is low. Addition of one part of anhydrous calcium chloride or magnesium chloride to two parts of barium chlorate results in a safe mixture. Sodium dichromate-organic matter mixtures are much less combustible than those containing chlorate, but these mixtures also are somewhat dangerous at ordinary humidities when there is a high proportion of sodium dichromate in the mixture. When 10% of anhydrous calcium or magnesium chloride is added to the sodium dichromate the resultant mixture is safe under ordinary atmospheric humidities, regardless of the proportion of organic matter present. Mixtures of sodium chlorate and sodium dichromate with organic material are extremely combustible.

Measurements made under a series of imposed conditions of heat load, dunnage spacing, and air flow were in agreement with previous work in this laboratory in demonstrating (a) the occurrence of appreciable permanent temperature gradients in material, whether exothermic or not, stacked in an air-cooled storage room, and (b) the possibility of markedly reducing these gradients by effective channelling of air through the stack. With end-to-end circulation, blocking of voids in the room was the most important single factor in minimizing intra-stack temperature differentials under the conditions of these tests. Further improvement was effected by the provision of optimum dunnage and by augmenting the air flow. It is to be inferred that with blocked voids, dunnage should be extended to all external surfaces of the stack. The desirability of uniform transverse and vertical distribution of the circulating air was also evident. Further trials on a larger scale are required to explore the practical implications of ...

The rate at which poultry is frozen has been shown to have no effect on the number of bacteria present, and little, if any, effect on the extent of surface desiccation or development of visceral taint. The development of taint appears to depend primarily on the period during which the product is held at temperatures above the freezing point, and little advantage is gained by freezing promptly after slaughter, since taint development occurs during thawing.A quantitative study of the amount of fluid exuded (drip) after freezing and thawing whole birds shows that, regardless of the rate of freezing, the whole bird does not drip. Freezing does change the condition of the water in the muscle, however, since drip can be obtained from minced meat after freezing. If minced meat is frozen within 3 hours of slaughter, the amount of drip is somewhat variable but apparently independent of the rate of freezing. If the birds are stored for 24 hours or more at 0 °C., prior to freezing, the typical curved relation between the amount of drip and the freezing rate is obtained, the drip decreasing as the freezing rate increases.Using a constant rate of freezing (2.5 hours to pass from 0° to − 5 °C.), the amount of drip decreases as the storage time prior to freezing is increased. During storage at 0 °C., the greatest decrease occurs during the first day, but continues for periods up to 2 weeks. At 10 °C., little decrease occurs during the first 5 days, after which it decreases slowly until the product spoils. The amount of drip obtained at a given rate of freezing appears to be proportional to the amount of fluid obtained from the unfrozen material, showing that the drip is determined by the condition of the water in the original minced muscle. There were some indications that the state of the water in the tissue was partly determined by the pH, but the results were not conclusive.

The quantity of drip obtained from meat frozen at a constant rate is affected by the period between slaughter and freezing, and the pH of the tissue. These two factors appear to act independently, and only the latter was studied extensively. In precooled meats the maximum amount of drip was obtained at about pH 5.2, and as the pH increased the net drip decreased to zero at about pH 6.4. Pork, beef and mutton behave similarly both with respect to the form of the drip-pH relation and the quantity of drip exuded at a given acidity. Beef is normally more acid than the other meats tested, and this can account for its greater tendency to drip in commercial practice.Microscopic studies showed that large crystals were always produced by slow-freezing, regardless of the pH of the material. The absence of drip from slowly frozen tissue at pH 6.4 is therefore not due to crystal size, but must be attributed to the greater re-absorbing power of the proteins in this region. Protein denaturation does not affect the quantity of drip obtained when meat is slowly frozen or stored for periods up to three days in the freezing zone. The weak re-absorptive power of the proteins at pH 5.2 must be attributed to their isoelectric condition in this region, rather than to their denaturation. It is only in this isoelectric region that the production of small crystals by quick-freezing will reduce the quantity of drip.

Chemicals applied to annual weeds frequently gave dosage-mortality curves that were not of the usual sigmoid shape. These departures appear to be attributable to the method of application, as the spray is only partly retained by the leaves and stems. The proportion of the applied quantity of poisonous constituent retained by the plant decreases as the volume of spray is increased, and increases as the concentration of the spray solution is increased. Leaf sprays will therefore be most effective if the minimum volume of solution required for coverage is used, and the effective dosage of the chemical obtained by adjusting the concentration.A few indices sometimes used for estimating the efficacy of herbicides were compared with the mortality criterion. The number of leaves left, and the height of the living plants after treatment are of little or no value for estimating the effect of the chemical. The weight per unit area of the living plants remaining after treatment may be of some value.

The viscosity of gluten dispersions in sodium hydroxide and acetic acid always decreased during heat treatment, the magnitude of the decrease being much larger in the former than in the latter solvent. Dispersions in urea solution decreased to a fixed viscosity level at temperatures below 70 °C., but at higher temperatures the initial viscosity decrease of dilute dispersions was followed by an increase, then again by a decrease. At 60 °C., dispersions in sodium salicylate increased in viscosity throughout the period of heat treatment, but at 80 °C. the viscosity increased to a maximum and then fell off. This qualitative difference in the viscosity changes at temperatures above and below 70 °C. in the neutral solvents, was the only evidence obtained to indicate that dispersed gluten undergoes any sudden change in character at a certain temperature, comparable to the so-called "coagulation point" of albumins. The results indicate that the changes occurring below 70 °C. can be attributed mainly to the action of the solvent on the protein.

Twelve chemicals previously found to be highly toxic to annual weeds were applied to a perennial weed in three different ways, viz., to the foliage only, to the soil only, and to both the soil and foliage. The chlorate ion was found to be most toxic, but sodium selenite, ammonium thiocyanate, sodium dichromate, and sodium arsenite were all reasonably effective at higher dosages. None of the other chemicals caused any significant, permanent reduction in growth at the dosages used. The permanent effect of a treatment appears to be due almost entirely to the action of the chemical in the soil, and the ineffectiveness of certain chemicals can be attributed to their rapid detoxication by the soil. Although all the chemicals exert a temporary, and in some cases, a slight permanent effect, when applied to the foliage only, this method of application is generally ineffective owing to the inability of the leaves and stems to retain or absorb a lethal dosage.

Small cuts of matured Wiltshire bacon were held at temperatures of 20, 40, 50, 60, 70, and 80 °C. for periods of 5, 10, 20, and 40 hours. When the nitrite content after treatment was plotted against the temperature, the results showed that the highest nitrite contents were obtained at 40 °C., the nitrite content decreased logarithmically between 40 and 80 °C., and the slope of these curves increased with increasing periods of treatment. The curves representing the different periods of treatment intersect in the region of 55 °C., where the nitrite content was approximately normal. It appears, therefore, that an increase in nitrite content above the normal level occurred at temperatures below 55 °C. and a decrease at higher temperatures. This decrease in nitrite nitrogen above 55 °C. may be attributed to direct loss, oxidation, or reaction with the constituents of the meat. The increase in nitrite observed at temperatures below 55 °C. suggests that time and temperature were not alone responsible for the observed changes, since comparable increases in nitrite were not observed in commercial cuts. It may be that the proportionately greater surface exposed to the air in these small samples may have had some effect, such as an enhanced aerobic bacterial action.

The electrical moisture meters studied were: the Burton-Pitt, Davies, Limbrick, hand-operated and motor-operated Tag-Heppenstall. The Burton-Pitt is a "dielectric" type; all the others depend on the resistance principle.The calibration curve for the Burton-Pitt instrument is parabolic within the range 11.0 to 17.0% moisture. The resistance type instruments all show a linear relation between moisture content and the logarithm of the resistance at moisture contents below 17.0%, and a parabolic relation at higher moisture contents. The accuracy of the meters, as determined by the experimental errors and the standard error of prediction of the vacuum oven moisture, decreases in the following order within the moisture range, 11.0 to 17.0%: motor-operated Tag-Heppenstall, Limbrick, hand-operated Tag-Heppenstall, Burton-Pitt and Davies. At higher moisture contents than 17.0% the Burton-Pitt and Davies instruments are definitely unreliable, and the remaining meters are also less precise.The temperature coefficient of the wheat-instrument system was found to be appreciably different from that of the wheat alone in the Limbrick and Burton-Pitt. The temperature coefficient was also found to differ somewhat in different moisture ranges. The effect of humidity is most pronounced in the Limbrick, but is in all instruments small in comparison with that of temperature. The limited number of low grade samples studied appeared to follow the same calibration curve as high grade samples in all meters and 28 samples of the hard-kernelled variety Garnet were also found to follow the calibration curve deduced from the general reliability experiments in all meters, with the exception of the hand-operated Tag-Heppenstall. The discrepancy with this meter is not great and can be attributed to the roll space being unsuitable for this hard-kernelled variety.The moisture range satisfactorily covered by the instruments decreases in the order: motor-operated Tag-Heppenstall, hand-operated Tag-Heppenstall, Limbrick, Burton-Pitt and Davies. In all cases the upper limit is finally determined by the increasing inaccuracy of the meter, rather than by its physical range, which is limited at 21.5% moisture with the Limbrick only when used at the highest sensitivity. With wheat below 11.0% moisture, only the Burton-Pitt and Tag-Heppenstall instruments can be used, and the calibration curve for the Burton-Pitt obtained with wheat of higher moisture content cannot be extrapolated over this lower range.

Wiltshire bacon, cured in pickles of various compositions, was smoked after various maturation periods, and compared with corresponding unsmoked samples during subsequent storage at −9.4 °C. Curing practices designed to obtain milder cures were only partly successful, but in all instances it appears that smoking improves the keeping quality.Smoking reduced the number of surface bacteria to approximately 10−4 times the number present before smoking, and effectively retarded growth during storage. The fat of the smoked bacon was much more resistant to the development of rancidity than that of unsmoked bacon. The colour of smoked bacon was significantly lighter than the unsmoked material, and tended to darken more rapidly during storage. Flavour was superior in the smoked samples. From the reduction in bacterial numbers, rate of bacterial growth, and rate of rancidity development, it would appear on the average that smoked bacon would keep about twice as long as unsmoked bacon under comparable conditions.

Substances previously found to be highly toxic when applied to annuals as a spray were also found to be most toxic when added to culture solution. The results by the two methods, however, do not agree as far as the less poisonous chemicals are concerned, certain substances being comparatively more toxic in culture solution than as a spray, and vice versa. These discrepancies can be explained by the fact that the dosage in culture solution was varied by adjusting the concentration, whereas in the spraying test it was varied by altering the volume of spray.The time between treatment and death of the plant generally decreases as the dosage is increased over a limited dosage range, but varies with different chemicals, and appears to be independent of their inherent toxicity.The size of the plant is seriously reduced at dosages that produce no mortality. The final weight, however, was unsatisfactory as a criterion of toxicity since it was extremely variable. The interfering factors affecting the final weight were taken into account by computing the relative growth rate. The curve relating growth rate and dosage is slightly concave upwards when the dosage is plotted on an arithmetical scale and linear when plotted on a logarithmic scale. The position and slope of the line depends on the chemical. The standard error of duplicate tests increases as the growth rate decreases. On the average, complete mortality occurred at a growth rate of − 2.44% per day under the conditions of these experiments, but this is subject to variation due to differences between duplicates, chemicals, and series (plants grown at different times).Analyses of the culture solutions containing chlorates showed that the amount of chlorate taken up by the plant increased with the concentration present in the culture solution. Nevertheless, only a small, relatively constant proportion of the chlorate present was taken up by the plant at all concentrations.

The pH of bacon was relatively uniform, but it was possible to demonstrate statistically significant differences between sides cured in the same plants. Sides from different plants were however no more variable than those from the same plant. The results indicate that the pH of the bacon is affected by the pH of the pump pickle, decreases with the time in cure, and increases with the age from cure.The absolute values of the Eh potentials observed in bacon were doubtful, but since the measurements indicated a statistically significant difference between sides from different plants it appears that this property may be a function of curing practice. Although the moisture content of bacon was relatively uniform, there was a significant difference between sides from different plants, and a significant loss of moisture during maturation and smoking.The protein content of the tank pickle from different plants varied considerably, and probably reflects the effect of different handling practices. Nevertheless it was possible to demonstrate a direct relation between protein content and pH of the pickle.

The previous study has been extended to include durum wheat, barley and oats. The hand-operated Tag-Heppenstall meter was found to be unsatisfactory with these grains, as they would not feed into the roller electrodes in a suitable manner. The Burton-Pitt gave erratic results with these grains and it was only possible to calibrate this meter over a limited moisture range, and even over this range it was more inaccurate than the other meters. Qualitatively the calibration curves for these three grains, in the Limbrick and motor Tag-Heppenstall, were similar to those previously obtained with hard red spring wheat. The actual resistance and the slope of the curves were, however, somewhat different for the different grains. The standard error of prediction shows that the motor-operated Tag-Heppenstall was the most accurate meter for use with durum wheat and barley, while the Limbrick was superior with oats. With the limited number of samples available it was impossible to detect any significant difference between the temperature coefficients, in any particular meter, of the different grains. When converted to a moisture basis the correction factors were practically the same as for hard red spring wheat.The results from the entire investigation show that the Brown-Duvel method is more accurate than the 130 °C. air oven method with all grains studied. The motor-operated Tag-Heppenstall meter is as accurate as the Brown-Duvel with hard red spring wheat, over the moisture range 11.0 to 17.0%, and is superior to the air oven method over this limited range. Otherwise the rapid analytical methods are more accurate than any of the moisture meters tested with any of the grains. The meters fall in the following order of decreasing accuracy over the moisture range 11.0 to 17.0%:–with hard red spring wheat; motor Tag-Heppenstall, Limbrick, hand Tag-Heppenstall, Burton-Pitt and Davies: with durum wheat and barley; motor Tag-Heppenstall, Limbrick and Burton-Pitt: and with oats; Limbrick, Burton-Pitt and motor Tag-Heppenstall. Where a meter is not mentioned no tests were made, the instrument having been omitted because it gave no promise of practical utility.