368 
Journal of Agricultural Research 
Vol. XXIV, No. s 
TABiy^ IV. —Analysis of butter fat 
Colantha 
II. 
Samantha 
II. 
Cecile II. 
Peggy. 
Saponification number {s)... 
.mgm.. 
229.466 
230.324 
230.907 
230.968 
Acid number (a). 
.927 
2.386 
1.626 
3-657 
Ether number {e) . 
.mgm.. 
228.539 
227.938 
229.281 
227-311 
lodin number. 
30.622 
29.605 
28.159 
22.720 
Equivalent in oleic acid.... 
. .per cent.. 
34-063 
32.931 
31-323 
25-273 
Total fatty acids (T) (i.oo- 
■0.00022594 
! 
«). 
94.836 
94.850 
94.820 
94.864 
Neutralization number 
(n) sIT 
241.961 
242.830 
243-521 
243-473 
Free fatty acids (A ) ajn .... 
.. per cent.. 
*383 
■983 
.668 
1.502 
Soluble fatty acids (5) {T—I) 
6.470 
7.023 
7.226 
6.510 
Neutralization number.... 
.mgm.. 
503.184 
513-356 
517.409 
495-637 
Insoluble fatty acids (I) by alcoholic 
potash. 
88.366 
87.827 
87-594 
88.354 
Neutralization number.... 
.mgm.. 
222.835 
221.197 
220.927 
224.893 
Stearic acid by crystallization 
.. per cent.. 
13-709 
16.997 
20.321 
13-398 
Glycerol (0.00054703 e) . 
. .per cent.. 
12.502 
12.469 
12.542 
12.435 
The percentages of total fatty acids were 94.843 in the Holsteins and 
94.842 in the Jerseys and their neutralization numbers 242.396 and 
243.497 mgm., respectively. The percentages of free fatty acids were 0.683 
and 1.085, indicating a greater tendency to hydrolyze in the Jerseys. 
The percentages of soluble fatty acids were 6.747 and 6.868, and their 
neutralization numbers 508.270 and 506.523. The percentages of insol¬ 
uble fatty acids were 88.097 and 87.974, and their neutralization num¬ 
bers 222.016 and 222.910. The nature of these differences is apparent 
from the data, but the extent can not be actually apportioned with five 
components involved. The two breeds showed a remarkably close agree¬ 
ment in the several groups of fatty acids and of glycerol, but the propor¬ 
tion of high molecular weight acids in the insolubles was slightly more 
pronounced in the Holsteins. 
The composition of neither breed conformed particularly to that of the 
herd sample (Table I), although the difference in actual percentage of 
soluble and of insoluble acids was more appreciable than the difference in 
proportion of constituent acids in each group, as indicated by the neutrali¬ 
zation numbers. 
ESTERIFICATION PROCESS 
The method (7) of esterification, purification, and fractionation of the 
ethyl esters remains substantially as published. Attention might be 
called, however, to some minor modifications that have since been 
adopted. Alcohol for esterification is prepared by distilling approxi¬ 
mately 2 liters in a water bath over 600 to 700 gm. of granulated caustic 
lime (95 per cent CaO) and 30 to 40 gm. of yellow ceresin wax and re¬ 
distilling over fresh lime and ceresin until free from water, as indicated 
by the absence of lime from solution. On the final distillation the first 
and last portions are rejected for additional treatment and the main por¬ 
tion is preserved. This process has proved the most reliable so far tested. 
Three cc. of concentrated sulphuric acid have been substituted as a 
catalyzer in place of dry hydrochloric acid at a material saving in 
time and convenience and considerable gain in efficiency. 
