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Permeability of the vasculature of methylcholanthrene-induced brain tumors has been studied by tracer injection of fine carbon-black of a nearly standard particle size of 200 Å. After the first week of growth vessels of these tumors have shown increasingly abnormal permeability for particles of this size. Such defects have appeared first in the thin-walled veins and venous sinusoids and later have involved capillaries throughout each tumor. Arterial brandies have been spared. [ABSTRACT FROM AUTHOR]

The section of "Chemical Testing and Analysis," focuses on detergents and their characteristics. According to a research done, the enzyme additives present in detergents helps in stain removal by effective breakdown of proteinaceous and starchy components of blood, urine, sebum and natural perspiration. It is mentioned that most of the artificial soiling media, used in detergency experiments, contains carbon black but ferric oxinate or oxides of chromium and iron could also be used. It is stated that under experimental conditions two factors determine the efficiency of detergents, namely cleanliness and oil removal.