1909.] PUBLIC DOCUMENT — No. 31. 85 



The saponification or Kottstorfor value rej^resents the num- 

 ber of milligrams of i3otassiiini hydrate necessary to completely 

 saponify one gram of fat. In case of butter fat, Brown ^ states 

 that the probable mean- is 228.5, with extremes of 22-1 and 

 234.9; Thorpe'^ shows variations of from 219.7 to 232.6. 



In butter fat a high saponification value is accompanied by a 

 relatively high Reichert-Meissl value and a relatively low iodine 

 value. This is natural, for a high percentage of oleic acid 

 having a low combining j^ower would increase the amount of 

 iodine absorbed; and, vice versa, an increase in the percentage 

 of soluble fatty acids of high combining power (Reichert-Meissl 

 value) would increase the saponification and dej)ress the iodine 

 value. 



In the first period it is sho^vn, in the above table, that both 

 herds produced butter fat with relatively high saponification 

 values ; such a condition may be considered characteristic of 

 the animals, all of which were grade or pure-bred Jerseys and 

 none in an advanced stage of lactation. Herd I. vielded a fat 

 with a little higher saponification value than Herd II. The 

 former herd likewise showed a higher Reichert-Meissl'* and a 

 lower iodine value.^ The melting point ^ of the fat produced 

 by Herd I. was also a trifle higher than from Herd II., although 

 this test is not sufficiently delicate to enable one to place much 

 value upon it. 



The results of the various determinations all point to the 

 fact that in the first period, with both herds receiving the same 

 ration, Herd I. yielded butter fat with slightly less insoluble 

 fats (especially olein) and slightly more soluble fats than 

 Herd II. 



In the second period, in case of Herd II. 2.3 pounds per day 

 of soy bean meal replaced a like amount of normal ration. It 

 may be recalled that the partially extracted soy bean meal as 

 fed contained some 45 per cent, of protein and 9 per cent, of fat, 

 while a normal soy bean meal averages about 35 per cent, pro- 

 tein and 18 per cent. fat. The influence of the bean on the 



1 Pennsylvania Experiment Station, report, 1899-1900, pp. 226 to 245. 



2 Average of 40 samples. 



3 Lewkowitsoh, third edition, A'ol. II., p. 834, calculated from 357 English analyses. 



4 Leffmann-Hcam modification. 

 6 Wijs' modification. 



8 Wiley method. 



