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The present paper shows and discusses microphotographs of fibres used for the manufacture of cigarette papers as well as such photographs disclosing the composition of cigarette papers.

The influence of air permeability of cigarette paper on the yield of condensate and on its composition was examined. Total particulate matter and nicotine in the smoke decrease with increasing permeability of the paper. The decrease results from the smaller quantity of tobacco burnt in the mainstream. Higher combustion cannot be obtained by paper of greater permeability. The content of condensate of 3,4-benzopyrene is constant. Total particulate matter and nicotine in the smoke - measured in per cent of the tobacco smoked in the mainstream - are also constant.

Ten sorts of cigarette paper with differing physical properties, made of the raw materials Iinen, sulphate cellulose and “viskose”, which had been impregnated with citrate, phosphate or nitrate, were examined. The cigarettes made from these, which all contained the same blend of tobacco, were 7.95 × 80 mm and had an average weight of 1.070 g at 11.5 % moisture, were compared with each other in taste and in laboratory tests. A variation of the surface weight between 20.5 g/m2 and 24.5 g/m2 had no noteworthy influence on the properties of the cigarette. For the impregnation of the paper citrate is more desirable than the other salts investigated. The cigarettes made with paper impregnated with citrate provide the best looking ash and were favoured by the smokers of the taste panel. Cigarettes made with paper impregnated with nitrate and phosphate are stronger and more mordant and, furthermore, they have a bitter “after taste”, except those made with “viskose” paper. As the porosity of the paper increases the totaI condensate amount decreases. The “smouldering speed” of the cigarette increases somewhat. The members of the taste panel in each case preferred the milder cigarettes with the more porous paper. Paper made from linen, the most usual raw material nowadays for making cigarette paper, was compared with sulphate cellulose and “viskose” paper. Paper of sulphate cellulose is by comparison not very porous and gives the cigarette's taste tart qualities. “Viskose”, on the other hand, can be used to make very porous paper, the physical qualities of which come up to or even exceed those of linen paper. It was not possible to prove by the tests whether “viskose” paper negatively influences the taste of the cigarettes.

The ''porosity'' or ''air permeability'' of cigarette tissue is measured by many different instruments, is expressed in various units and it is frequently impossible to correlate such measurements and the readings of such instruments. The property of a paper whereby it allows air and gases to pass through it while still containing the burning tobacco rod is of great and increasing interest in both the Research Laboratory and Raw Material Control Laboratory of the cigarette and filter rod manufacturer. Interest in papers of higher air permeability continues to grow, particularly in regard to the so-called ''Health Hazards of Smoking", and thus the effect of smoke dilution. Such interest by the cigarette and filter rod manufacturer necessarily means that the paper manufacturer must pay especial attention to this property during paper manufacture and in development work. He also requires to define and measure the property in his control and research laboratories. Unfortunately, there is no common language to describe this property and as interest in higher porosities grows so the shortcomings of some methods of measurement are highlighted. The situation is further complicated by the need of control laboratories for robust, simple to operate instruments, while a research laboratory might be more interested in accuracy and precision, while being less affected by the demands of careful operation and manipulation. Likely sample sizes can also vary, from small spills cut from individual cigarettes or rods, through long narrow skeins to the papermakers' sheets. A standard definition of air permeability of a sheet of paper has therefore been proposed and an instrument has been designed, using this definition, to meet the requirements of all interested parties. A number of these instruments have been built and proved by practical usage

A simple method for the determination of the balance of carbon-14 activity added to cigarettes is described. The total recovery of activity is 80 % or greater, and the method can be used to obtain information on the transfer and pyrolysis reactions occurring when cigarettes are smoked.

A method for preparing cigarettes from ground tobacco is described and suggested as a simple means of comparing smoke yields of total particulate matter and nicotine. It is shown that yields from cigarettes made from ground and from cut tobacco are highly correlated.

According to the formulae the pressure drop R (l) and the degree of ventilation V (l) of cigarettes depend on the length l of the cigarette without tip, on the pressure drop RG of the incandescent zone alone, on the specific resistance to air flow b of the tobacco rod, on the specific conductivity a of the paper wrapping, and on the pressure drop RM of the ventilation-free cigarette tip. The parameters a and b are defined by the equations respectively, for the pressure drops RT and RP of the tobacco rod only and of the paper wrapping alone. In practice, the cigarette can approximately be considered as "ohmic" resistance to air flow, i.e. there is a linear relationship between pressure difference and flow rate. The degree of ventilation is the part of the total stream which penetrates the paper wrapping of the cigarette. The indicated relationships were theoretically deduced and empirically confirmed. The formula for R (l) corresponds to In general, there are the following relations where U1 is the total decrease of pressure occurring along both cigarette without tip and incandescent zone, I1 is the total stream leaving the cigarette at the cigarette tip, U2 is the decrease of pressure occurring along the incandescent zone, and I2 is the air stream which flows into the cigarette through the incandescent zone. The connections between U1, I1, U2, I2 and R, RG, V are as follows

Cholesterol-4-14C and b-sitosterol-4-14C were incorporated into cigarettes and their presence in mainstream smoke was studied. The transfer of 14C-labelled cholesterol to mainstream smoke was 20.27 %, of which 16.25 % was in trapped smoke condensates and 4.02 % in butts; only 0.004 % was in ashes. The transfer of 14C-labelled b-sitosterol to mainstream smoke was 16.20 %, of which 13.11 % was in trapped smoke condensates and 3.09 % in butts; only 0.007 % was in ashes. The relative composition of free sterols, steryl esters, and bound glycosides in cigarette tobacco and in trapped smoke condensates was also studied. Fractions of free sterols and steryl glycosides were higher while fraction of esters was lower in trapped smoke condensates as compared to cigarette tobacco. Comparison of four individual sterols (cholesteroI, campesterol, stigmasterol and b-sitosterol) was studied in cigarette tobacco and cigarette smoke (smoke condensates, butts, wrapping papers from butts). A slight increase of cholesterol was noted in smoke condensates and wrapping papers from butts.

There have been various references in the literature to the levels of trace metals in natural products (1., z, 3). There have also been references to the level of cadmium found in tobacco smoke (4). We have, in the past, accepted the published data of other workers in this field (5, 6) but recently we have made our own evaluation of the level of cadmiwn, nickel and lead in tobacco and cigarette smoke. The work described in this paper had two objectives: firstly to determine, using re

This paper describes a method for the extraction, separation and determination of amino acids, both free and protein-bound, which are present in tobacco. The introduction of the lyophilization process and the ''cold finger'' technique made it possible to obtain a good purification of extracts which, unlike the previous methods, have been preserved for a long time. The combined use of column chromatography and mass spectrometry enabled all amino acids present to be detected. The analyses carried out on different tobacco varieties showed certain quantitative and qualitative differences in the composition of amino acids and only small quantitative variations in the composition of protein-bound amino acids

The cold pentane traps of the precipitation procedure described in the preceding paper (cotton wool trap, water trap, pentane traps) favour the formation of N-nitroso components and, as a result, the emergence of artefacts. If, however, the smoke sojourns in the aerosol state for a period of 40 seconds (compared to 5 seconds) also that part of condensate of smoke from cigarette tobaccos rich in nitrates and bases which is trapped on cotton wool at normal temperature, contains N-nitroso-dimethylamine and N-nitroso-pyrrolidine in quantities corresponding to 0.004 µg N-NO per cigarette. The formation of N-nitroso components in the smoke of tobaccos of high nitrate and base contents accordingly occurs during a gas phase reaction which is dependent on time.In conformity with the previously reported findings N-nitrosomethyl-n-butylamine was identified in the condensate gathered in pentane traps. Presumably, it has however to be regarded as an artefact produced by the precipitation system employed. Condensates collected in cold and acetone traps were found to contain more N-nitroso components than condensates precipitated simply by the gas phase reaction of the smoke. The quantity of N-nitroso components contained in condensates gathered in cold traps was found to increase during aging.Model experiments with pure substances showed that the formation of N-nitroso components in the gas phase requires the presence of a mixture of NO and NOThe competitive reaction of dimethylamine and methanol with the gaseous mixture of nitrogen oxides displays the prevailing formation of N-nitroso-dimethylamine. The yield of N-nitroso-dimethylamine in NO-air-mixtures is probably only dependent on the rate of the oxidation NO undergoes to NONitramines cannot occur in smoke.

The present paper gives an account of tests carried out with the automatic ''Coleman'' apparatus to determine the nitrogen content of tobacco. Preliminary experiments made with different tobacco types led to the determination of optimum operating conditions which give exact and reproducible results. The values obtained by this procedure are the same as, or slightly superior to, those obtained by using the Kjeldahl method associated with the use of an efficient catalyst.

An automated smoking machine, and improved associated equipment, has been described. The automatic portion consists of a "string cut-off" technique which instantly and accurately stops the puffing action on cigarettes. This is achieved by an electronic sequence that deactivates three-way solenoid valves and vents the smoking train to the air at the syringe. Solenoid deactivation is achieved through the use of microswitches and relays. An automatic puff-counting unit records the number of puffs taken on the cigarettes on each port. The counters are pulsed by a signal generator set for 5 pulses per second. The generator is activated by a 2-second cam and microswitch attached to the 4-second cam that cycles the smoking machine. Constant puff volume and puff duration are maintained by use of individual syringe eccentric cams that allow precise volume adjustment on each port and solenoid valves that serve as intake and exhaust valves and provide positive action. The solenoid valves are activated by the 2-second cam and microswitch that is synchronized with the puffing downstroke of the syringe. The 2.0 AA± 0.2-second puff is precisely obtained through the machine's variable speed controlled gear driven electric motor. This feature yields a stable volume and duration regardless of the resistance of the cigarettes. The level of precision obtained previously on the O'Keeffe and Lieser machine was reduced by one-third by the automation developments described in this paper.