PUBLISHED BY THE ALUMNI ASSOCIATION 

 OF THE COLLEGE OF PHARMACY OF THE CITY OF NEW YORK. 



LIBRA 



NEW Y< 



BOTaM 



GAF^iOl 



Vol. 1. 



New York, December, 1894. 



No. 8. 



NOTES ON THE TESTING OF OILS AND FATS. 



By H. T. VULTE;, Ph.D. 



T N the various text-books treating this 

 * subject there is a great fund of infor- 

 mation, too much, in fact, for the ordi- 

 nary observer, who becomes bewildered 

 by the vast collection of what appears to 

 be unassimilated material and he turns 

 away, impressed with the idea that much 

 study and experience are requisite io 

 order to pursue any investigations in 

 this most fascinating branch of organic 

 analysis. 



A comprehensive scheme for the test- 

 ing of oils and fats may not be laid down 

 with the inflexibility of the schemes of 

 mineral analysis, but such a method as 

 will serve in the majority of cases can 

 be outlined with comparative ease. By 

 applying these tests much useful infor- 

 mation may be obtained, and it is not 

 difficult then to compare these results 

 with the figures obtained by former ob- 

 servers, and to judge with certainty of 

 the purity and character of the samples 

 in question. 



Many of the recorded results of tests 

 are of questionable value, and some of 

 the information utterl}^ unreliable — of 

 this character are the various color re- 



actions with acids, all of which are un- 

 certain except those with sulphuric acid, 

 and even this test must always be made 

 in comparison with a sample of known 

 purity and under scrupulously exact 

 conditions. 



A brief discussion of the constitution 

 of oils and fats is not out of place in this 

 article, and the subject may be so ar- 

 ranged as to simplify the usual complex 

 classification. The ordinary distinction 

 of oil and fat is one of temperature sole- 

 ly, and not of constitution, as it should 

 be ; it is better, then, to arrange these 

 bodies in two great classes, viz : Fats, or 

 true glycerides compounds of the fatty 

 acids, bodies containing carbon, hydro- 

 gen and oxygen, with the tertiary alco- 

 hol, Glycerole. If these compounds are 

 liquid at ordinary temperatures they may 

 be called Oils or Oleins, if solid, under 

 the same conditions, they may be called 

 fats or stearines. To this class belong 

 the fats of animal and vegetable origin. 



Hydrocarbons, bodies composed of car- 

 bon and hydrogen only, with the same 

 limitations as to temperature and state, 

 when liquid, usually called mineral oils, 



