214 . The Philippine Journal of Science 1920 
Woll(10) in his report on dairy products gives the following’ 
determinations of lactose in condensed milk: 
Lactose. 
Analyst. B : 
y gravi- 
metric By polar- 
method. iscope. 
Per cent.|Per cent. 
Jaffa and Stewart, California -__..-..----------------------------------------- 9.28 9.36 
Olson, Wisconsin....---.-.----.:------------------------- - -------------------- 9.91 9.19 
Jaffa and Stewart, California ___--.----.-------------------------------------- 8.11 8.00 
Thc eee ae wes oh css a hae cen eee cen nee 10. 87 10.74 
Pee er he SRT Spe Mae eae pe ey bp eens emi pe Meee ae OP or - 9.96 9.84 
He called attention to the fact that the results obtained with 
the polariscopic method are, in all cases but one, lower than 
with the copper reduction gravimetric method. His observa- 
tions were confirmed by the report of Patrick and Boyle(6) 
who, in their subreport on analysis of dairy products, gave the 
following results: 
Lactose. 
Sample No. By 
: Soxhlet By polar- 
method. iscope. 
Per cent.\|Per cent. 
2930 (Referee’s sample) ------ [See Se oe Ree oor ea Se ee 10.04 10.07 
B00 sees cases eases 10.51 10.19 
a a ee amare ana anew 10.69 10.57 
ST oa es i ne as So ae ae aap ece 10.15 9.97 
2529. SIGS Ps ER nae ey pee 9. 20 8.71 
2531 aide: ®t boi 
Folin and McEllroy(4) have recently succeeded in introduc- 
ing copper phosphate mixtures, the alkaline phosphate taking 
the place of tartrates, citrates, or glycerol in the analysis of 
sugars in urine, using a modified Benedict titration method. 
Folin and Denis(3) have applied this method to the determina- 
tion of lactose in milk and they claim that it gives accurate 
results. Their method as applied to milk is remarkably simple, 
for it does away with the preliminary preparation of protein- 
free filtrates, since albumin does not interfere with the titra- 
tion, and it therefore “eliminates the cumbersome ‘corrections’ 
for the volume occupied by the protein-fat precipitates.” In 
