21 



found that 0.863 gram of iodine was absorbed. 100 grams 

 of the fatty acid, therefore, would absorb 84.6 grams of 

 iodine, the iodine value, then, being 84.6. The neutra- 

 lization value of oleic acid is 198; its melting point is 

 14C; and its iodine value 90. We are dealing with an 

 unsaturated liquid fatty acid, whose melting point is 

 13C; neutralization value 191; and iodine value 84.6. 

 Oleic acid is an unsaturated liquid fatty acid with the 

 above given constants. The unknown approaches very 

 closely to oleic acid in these three values, and it is 

 permissible, under the circumstances, to consider such 

 unknown as oleic acid. 



The remaining insoluble lead soaps were now decom- 

 posed with hydrochloric acid and the liberated fatty 

 acids were extracted with ether. The ethereal portion 

 was pipetted off, washed with water, and the ether 

 evaporated. The residue weighed 1.84 grams. The iodine 

 value was 2.3, due, probably, to admixture of the un- 

 saturated acid previously described. We are dealing, 

 therefore, with two or more saturated fatty acids, since 

 it was found that about one-half of the mass melted at a 

 temperature of about 32C, while the remaining portion 

 did not melt until heated to a temperature of 68C. The 

 saturated fatty acids which have melting points between 

 30C and 35C are confined to one member, capric acid. 

 The saturated acids which melt between 65C and 70C are 

 confined, likewise, to one member, stearic acid. To sep- 

 arate these acids, when one has such a very small amount 

 of material, is hardly a feasible procedure. Nor can one 

 determine the analysis by the melting points, since such 

 acids form entectic mixtures which often have a melting 

 point higher or lower than any of the individual con- 

 stituents (27) . 



SUMMARY 



The Bacillus coli has been divided chemically into 

 two parts, one of a protein nature, the other fatty. The 

 protein portion alone is not an antigen in the sense that 

 it will give rise to the specific antibodies of the 

 bacillus coli. 



The fatty portion, on the contrary, contains the 

 substances essential for the production of specific anti- 

 genie reactions. 



