14 



grease to avoid complete saponification, and the resulting fatty acids showed up a 

 little cloudier than the 1 per cent mixture; still we could not detect it in the titer. 



It appears, then, that the error in the titer due to accidental failure to completely 

 saponify is ordinarily a negligible quantity. In the case of doubt, comparison by 

 the saponification test with a stock mixture of fatty acids and fat containing 1 per 

 cent of the latter can easily be made, when any sample showing no greater cloudi- 

 ness than this may be assumed to be not more than 0.1 C. lower in titer. The range 

 in the titer and general properties of the samples employed in the experiment seemed 

 wide enough to warrant such a generalization. 



These facts would seem to justify the referee in recommending n. 

 method combining the best features of both methods, as follows: 



PREPARATION OF FATTY ACIDS. 



Saponify by using aqueous or alcoholic potassium or sodium hydrate. If alcohol 

 is used it must be carefully removed. Dry the fatty acids in the manner prescribed 

 in the Dalican method, although they may be dried as in the Wolfbauer method if 

 desired. 



Always test the fatty acids for unsaponified matter, as prescribed by the Wolfbauer 

 method. The titer shall be taken in the manner described in the Wolfbauer method 

 and in the tubes prescribed. The room temperature should be reported. 



A letter was sent to the collaborators asking them to give their 

 opinion of this method as outlined, and the following signified their 

 willingness to accept it: 



A. Lowenstein, chemist of Nelson Morris & Co. 



Wilson Low, chemist Cudahy Packing Company. 



David Wesson, Southern Cotton Oil Company. 



Thomas Gladding, of Stillwell & Gladding. 



A. G. Stillwell, of the Stillwell Provisioner Laboratory. 



F. C. Weber, of the U. S. Department of Agriculture. 



M. H. Ittner, Colgate & Co. 



James Boyce, of the American Cotton Oil Company, and R. D. 

 Oiiar, of the W. J. Wilcox Lard Company, felt that the Dalican 

 method of stirring was more satisfactoiy. 



Dr. A. G. Manns, of Armour & Co., and his associates desired a 

 more complete drying of the fatty acids and showed that in their 

 experiments simply heating the fatty acids up to 150 C. and stirring 

 constantly was sufficient, giving the same results as heating four hours 

 at 105 C. 



A. V. H. Mory wished to specify that alcoholic saponification should 

 be used with cottonseed oil, the dangers of scorching the soap by the 

 Wolfbauer method of saponification being very great, as is shown by 

 his report. 



Albert H. Schmidt, of Schwarzchild & Sulzberger, was strongly in 

 favor of using the Dewar vacuum jacketed tube specially arranged for 

 the titer work and constantly shaking. This arrangement certainly 

 offers many advantages of convenience and accuracy, and his suggestion 

 as to the need of standard thermometers is important. 



