314 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS f• :) 4.0 '1o I I I J I I I I I I I I •12 G • lB 9 12. I$ •. 15' 16 19 2o 2 I Figure 8 4.0 of the effective material is well below the zero-effect line, and with the ineffective material it is centered about the zero line. It is hardly a profound ob- servation to note that one sweats more in hot weather than in cool. However, for the sake of curiosity, a graph was made of the average daily milligrams of perspiration from a group of 11 untreated arms versus the average daily temper- atures for the same days as obtained from the Weather Bureau. There is a pleasingly close correspondence of the ups and downs of the two curves as shown in Fig. 8. The month of April was chosen as giving a good spread of warm and cool days. In conclusion, it may be said that the apparatus described is simple, rugged, and easily con- structed. Only a few instructions and a little practice are required for operators to become proficient in its use. The procedure and method here described may, of course, be modified to fit the investigator's specific needs. REFERENCES (1) Kuno, Yas., "Physiology of Human Per- spiration," London, J. & A. Churchill (1934). (2) Minor, Victor, Zentr. ges. Neurol. u. Psychiatrie, 47, 800-803 (1927).

STABILITY TESTING OF LOW-PRESSURE AERO- SOLS* By Eu•v. Nv. L. Rosy. G. Barr & Company, Chicago, IlL THE LOW-PRESSURE aerosol tion. New propellants have been dispenser represents a relatively developed and have been made corn- new and highly functional type of mercially available. packaging. After the introduction The cosmetic industry was slow of the low-pressure insecticide aero- to start since the available corn- sol in 1947, the industry developed mercial containers did not conform very rapidly when the commercial to the design and packaging famil- market for this type of product iar to the cosmetic trade. Equally becameapparent. Manyotherprod- significant is the fact that most ucts were rapidly adapted, more or cosmetic formulations that have less successfully, to this type of aerosol market possibilities contain packaging. I say more or less materials that are chemically or successfully, not so much because of physically incompatible with the lack of market or interest, but necessary propellants. The im- because of haste in getting these portant progress made by the mate- products to the market without rial suppliers has created active in- proper pretesting in the available terest in the possibility of market- containers. ing cosmetic preparations. Co- It is interesting to note that lognes, suntan oils, personal deodor- during this relatively short space ants, shaving creams, shampoos, of time the containe? and valve and other hair preparations have manufacturers have greatly im- been successfuly marketed. How- proved their commercial runs of ever, considerable research and test- component parts to help make ing is necessary before a satis- the final products of the industry factory high-quality product can successful. Equally important is be marketed. the work done by the propellent It is the purpose of this .paper manufacturers who have cG-oper- to stress the importance of proper ated by releasing basic corrosion formulation and stability testing data and other technical informa- of aerosols to avoid failure and the resultant consequences. Mistakes in at the May18,1951, Meeting, the aerosol industry do not o,nl• New York City. *Presented 315