FAT 151 



excess of lead as sulphate and filter. Add 10 c.c. of 50 per cent 

 sulphuric acid and transfer the whole to a Kjeldahl flask provided 

 with a dropping funnel. The contents of the flask are distilled 

 and a solution of potassium bichromate is run in from the dropping 

 funnel at such a rate that the liquid always retains some yellow 

 color and the volume remains at about 100 c.c. It is rarely neces- 

 sary to add more than about 0.1 gram of bichromate and an 

 excess is to be avoided. Slow distillation is continued for two 

 hours and about 100 c.c. of distillate is collected. The tip of the 

 delivery tube must always remain under the surface of the water 

 in the receiving flask. Add 20 c.c. of hydrogen peroxide, make 

 slightly alkaline with NaOH and distill again. Catch the distillate 

 in small Erlenmeyer flasks containing ah excess of the Scott- 

 Wilson acetone reagent (at least 30 c.c. for each milligram of ace- 

 tone) and determine the acetone according to the procedure out- 

 lined in the preceding method for acetone and diacetic-acid. 



FAT 



Nephelometric Method of Bloor 1 



Principle. The protein is precipitated with alcohol and ether 

 and the fatty acid in the extract determined nephelometricalry 

 after saponification. 



Procedure. Extraction. About 2 c.c. of blood are drawn 

 from the vein with a graduated syringe and run at once with 

 stirring into a weighed graduated flask containing about 40 volumes 

 of a mixture of 3 parts alcohol and 1 part ether. After again 

 weighing to find the weight of blood added, the solution is raised 

 to boiling in a water-bath, cooled under the tap, made to volume 

 with alcohol-ether mixture, mixed and filtered. The filtrate is 

 water clear and almost colorless. 



Determination. From 5 to 20 c.c. of the extract (containing 

 about 2 mg. of fat) are measured with a pipette into a small beaker 

 and saponified by evaporating nearly but not quite to dryness 

 with 2 c.c. of N/l sodium ethylate. The residue is heated just 

 to boiling after the addition of 5 c.c. of alcohol-ether, and 50 c.c. 

 of distilled water are added. 



1 Bloor: Jour. Biol. Chem., 1914, 17, 377; 1915, 23, 317. 



