168 



Determination of casein in milk. 



From the results thus far obtained, the method appears to be a promising one. It 

 will probably require some modification to give uniform results. 



RECOMMENDATION. 

 It is recommended- 



That the referee for 1908-9 be requested to study the following subjects as fully as 

 may be practicable: 



(1) The official method for determining casein as indicated under 1. 



(2) The perfecting of the method for determining milk albumin. 



REPORT ON SUGAR. 

 By A. H. BRYAN, Referee, and FRITZ ZERBAN, Associate Referee. 



The work of the referee and associate referee upon sugar during the past year has 

 been substantially along the lines recommended by the association at its last meeting 

 and has comprised (1) work upon special methods of analysis in their relationship to 

 sugar chemistry; (2) work upon purely chemical methods; and (3) work by a number 

 of collaborators upon methods for the analysis of cane molasses and sugars. 



In the investigations of special methods the work has been confined very largely to 

 the study of the application of the refractometer to the estimation of dry substance in 

 the liquid sugar products. This study was published in the Journal of the American 

 Chemical Society Q and is not here repeated, but a recommendation based on the 

 work is made. 



The associate referee has confined his work mostly to the study of methods of esti- 

 mating reducing sugars, trying the Monroe-Neubauer crucible (a platinum gooch 

 with a filtering substance of platinum sponge), instead of the ordinary porcelain gooch. 

 The results are given in the Journal of the American Chemical Society. & 



The collaborative work consisted of two lines of determinations: (1) Methods .of mois- 

 ture determinations; (2) effect of clarifying agents on the polarization. Two samples 

 were sent out, one of a yellow sugar and the other an open kettle cane molasses. In 

 the circular letter sent out with these samples, the following instructions were given: 



INSTRUCTIONS. 



(1) Moisture on both samples. 



a) Two grams of material on sand to constant weight in vacuum oven at 70 C. 



b) Two grams of material without sand to constant weight in vacuum at 70 C. 



c) Two grams of sample on sand in water-jacketed oven for ten consecutive hours. 

 Weigh at end of ten hours. Then heat for two-hour intervals until weight is constant. 



(d) Repeat (c), but do not use sand. 



1908, 30: 1443. 



&1908, 30: 1456. 



