FATS. I 3 5 



moiety" of the protein, had been subsequently transformed into 

 fat and deposited as such in the tissues of the organism. Some in- 

 vestigators are not inclined to accept these data regarding the for- 

 mation of fat from protein as conclusive. 



The latest evidence in favor of the formation of fat from pro- 

 tein is furnished by the very recently reported experiments of 

 Weinland. This investigator worked with the larvse of Calliphora, 1 

 these larvae being rubbed up in a mortar 2 with Witte's peptone and 

 water to form a homogeneous mixture. After placing these mix- 

 tures at 38 C. for 24 hours the fat content was found to have 

 increased, as much as 140 per cent in some instances. The active 

 agency in this transformation of fat is the larval tissue since the 

 tissues of both the dead and living larvae possess the property. 

 Data are given from control tests which show that the action of 

 bacteria in this transformation of protein was excluded. 



EXPERIMENTS ON FATS. 



1. Solubility. Test the solubility of olive oil in each of the 

 ordinary solvents (see page 23) and in cold alcohol, hot alcohol, 

 chloroform, ether, and carbon tetrachloride. 



2. Formation of a Transparent Spot on Paper. Place a drop 

 of olive oil upon a piece of ordinary writing paper. Note the trans- 

 parent appearance of the paper at the point of contact with the fat. 



3. Reaction. Try the reaction of fresh olive oil to litmus. 

 Repeat the test with rancid olive oil. What is the reaction of a 

 fresh fat and how does this reaction change upon allowing the 

 fat to stand for some time? 



4. Formation of Acrolein. To a little olive oil in a mortar 

 add some dry potassium bisulphate, KHSO 4 , and rub up thor- 

 oughly. Transfer to a dry test-tube and cautiously heat. Note 

 the irritating odor of acrolein. The glycerol of the fat has been 

 dehydrolyzed and acrylic aldehyde or acrolein has been produced. 

 This is the reaction which takes place : 



CH 2 -OH CHO 

 CH-OH -> CH + 2H 2 0. 

 CIL-OH CH 2 



Glycerol. Acrolein. 



1 The ordinary " blow-fly." 



2 Intact larvae were used in some experiments. 



