1909.] PUBLIC DOCUMENT — No. 31. 95 



235.66 mgs. KoH required to saponify 1 gram fat. 

 213.89 mgs. KoH equals saponification number of insoluble fats. 

 86.66 equals per cent, of insoluble acids. 



.8666X213.89= 185.35 mgs. KoH to saponify insoluble acids 



in 1 gram fat. 

 235.66 — 185.35= 50.30 mgs. KoH required to saponify soluble 



acids in 1 gram fat. 

 50.30 H- .0803 = 626.46 theoretical saponification number of 



soluble acids. 



The mean molecular weight of the soluble acids was calculated 

 by the same formula as in case of the insoluble acids. 



The mean juolecular weight of the volatile acids was de- 

 termined bj evaporating to dryness the titrated portion resulting 

 from the Ileichert-Meissl number. From the weight of the 

 salts and of the alkali present in them the mean molecular 

 weight can be readily calculated by the following formula : — 



40 ■ 0.58 [salts — (c.c. N/10 NaOH X ■ 0040058)] 



c.c. N/10 NaOH X .0040058 + ^^-^ o 



10000 [salts— (c.c. N/10 NaOH X .0040058)] , .^ __ 

 c.c. N/10 NaOH. +18-016 



Every precaution was taken and blank determinations were 

 made on all of the reagents and deducted. 



The saponification number (S) of the volatile fatty acids 

 was obtained from the mean molecular weight (M), as fol- 

 lows : — 



Q 56158 



^- M 



The figures which follow represent the averages of analyses 

 made in the experiment described. Number I. includes an 

 average of all the data excepting those from Herd II. in the 

 third or soy bean oil period. Because the soy bean oil so dis- 

 tinctly modified the composition of the fat the average for this 

 period is j)resented by itself under Number 11. Number III. 

 represents the analysis of a sample of superior butter sent by 

 Gude Brothers of New York. Number IV. represents the 

 maximum and minimum tests usually recognized, with the 

 approximate averages. 



