
New York AGRICULTURAL EXPERIMENT STATION. 489 
by 0.004 per cent. of nitrogen, the excess being first with one 
method and then with the other. 
Second. That the individual results obtained by several deter- 
minations of the same milk agree closely by either method, 
somewhat closer accordance being given by precipitation at 
40°C. Thus, in sample No. 1, the greatest difference in three 
determinations was 0.006 per cent. of nitrogen at 40° C., and 
0.025 per cent. nitrogen with the other method. In sample No. 
2, the greatest difference was 0.009 per cent. nitrogen at 40° C- 
in three determinations and 0.011 per cent. nitrogen with the 
other method. . 
(2). Influence of amount of acid used in precipitating casein.— 
The acid used was a solution containing ten per cent. by weight 
of acetic acid. This dilute acetic acid was used in amounts 
varying from 0.5 to 5 cc. To about ten grams of milk, sufficient 
water at 40°-42° C. was added to dilute to 100 cc. and the acetic 
acid was then added. The operation was completed in the 
manner described above. 
Below we present the analytical results tabulated : 



Per cent. of 
“ay eee Character of filtrate. TH tee preci 
tate. 
ce. : 
( 0.5 ; Slightly cloudy ...... 0.458 
1.0 | Clear 0.458 
S eM Sh NAL NOE ea 6 (a8 16s dO) 6) 0.8.0, ave ° 
ample No. 1........ 4 LMS 14 OL OAT mini a cevve nc Gis lel clashes 0.449 
SOP Cleat tics rye ane nae are 0.441 
SOs Gleatiaw aan 0.475 
Teo CCAR a. akan cathe tie 0.474 
Be 0212 0 « 4 BeOS Clear ae so oe 0.469 
| 3.0 | Slightly cloudy ...... 0.450 
Paliyr mete Sach Mab Sy shots Ursa es OLE 
P.O. Quite-cloudy oly. 0.471 
oe Clear se ae 0.545 
Se ORO leary ens Woke, ait 0.550 
Sample No. 3........ 4 Pei Clear is cule inva tea 0.545 
Se eC leary sti ee see eo 0.537 
4.0 | Slightly cloudy ...... 0.527 
BOM Lal ype tek pea 5 AM 0.340 
(Pee Ose NEM al ky ual aieis Wi 0.059 
ample Noe. 4.20.0). 5 | 1.0 | Slightly cloudy ...... 0.551 
| Dy Ge: Clear ke pete thay Vane. 0.550 

