214 The Philippine Journal of Science 1920 
Woll(iO) in his report on dairy products gives the following 
determinations of lactose in condensed milk: 
Analyst. 
Lactose. 
By gravi- 
metric 
method. 
By polar- 
iscope. 
Per cent. 
9.28 
9.91 
8. 11 
10.87 
9. 96 
Per cent. 
9. 36 
9. 19 
8.00 
10. 74 
9. 84 
Do. 
Do ... 
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: 
Sample No. 
Lact 
By 
Soxhlet 
method. 
ose. 
By polar- 
iscope. 
Per cent. 
10.04 
Per cent. 
10. 07 
2530. 
10.51 
10. 19 
2528 
10. 69 
10. 57 
2610 
10. 15 
9.97 
2529 - 
9. 20 
8. 71 
2531- 
9. 37 
9.00 
* 
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 
