Xo. 6. DEPARTMENT OB' AGRICULTURE. 677 



Filsiugers's test is made us follows: Two grams of the fat are 

 placed in a graduated test tube and dissolved in G c. c. of a solution 

 containing four volumes of ether (sp. gr. 0.725) and two volumes of 

 alcohol (sp. gr. 0.810), the tube is then tightly corked and the con- 

 tents allowed to cool gradually. The temperature at which a de- 

 posit occurs is «oted, also the amount of deposit as the temperature 

 is lowered. In case of pure cocoa fat it is said that Filsinger's test 

 gives a solution which remains clear even on cooling to 0° C. My 

 own observations, however, lead me to conclude that this statement is 

 incorrect. Filsinger's test on lowering the temperature to 0° C. has 

 in my hands on several occasions yielded a decided deposit from 

 cocoa fat of known purity. Furthermore, many samples of cocoa 

 butter from different manufacturers and the fat from many brands 

 of chocolate have given heavy deposits at 0° C. by the above named 

 test, although no further evidence of adulteration could be detected. 



This fact, however, does not detract from the value of Filsinger's 

 test as it is not necessary to adopt so severe a standard as O C. It 

 will be observed in Table III that all the adulterated samples of 

 cocoa fat showed a decided deposit at 25'' C. and at 8° C. the deposit 

 almost filled the liquid. In any case wheo Filsinger's test is of value 

 1 believe a decided deposit will appear at or above 10° C, and so 

 far as I have been able to observe, pure cocoa fat does not give a de- 

 posit at so high a temperature as this. 



Additional evidence as to the character of the fat deposited by 

 Filsinger's test can be obtained by proceeding as follows: Remove 

 the supernatent liquid and dissolve the deposited fat in a small 

 <iuantity of ether. Plug the mouth of the test tube with cotton wool 

 and set aside until the ether has partially evaporated. In case beef 

 fat or lard be present, a crystalline deposit will be formed which, 

 if mounted in cottonseed oil and examined by the microscope, will 

 show the characteristic appearance of the crystals of the one or the 

 other of these fats. If however the sample be pure cocoa fat, there 

 will be no crystalline deposit formed at ordinary temperatures (65^ 

 to 80° F.) until the ether has entirely evaporated. In fact, judging 

 from my own observations, I am inclined to believe that cocoa fat 

 does not crystallize at all from solution io ether at ordinary tem- 

 peratures. The cr3'stals which finally appear are probably due to 

 segregation taking place in the liquid fat remaining after the 

 evaporation of the ether. 



The following table gives the results of the examination of the 

 fat of a few samples of chocolate. The abnormal figures indicated 

 in this table led me to regard the samples as adulterated, probably 

 with a product of cocoanut or palm nut oil. Although such determi- 

 nations as indicated in this table have been made upon many samples 



