FOODS AND FEEDING STUFFS. 49 



Table for the determination of lactose (Soxhlet-Wein) Continued. 



<b) DETERMINATION REQUIRING THE USE OF ALLIHN'S MODIFICATION OF FEH- 

 LING'S SOLUTION. PROVISIONAL. 



(1) PREPARATION OF REAGENTS. 



(a) Copper sulphate solution. Dissolve 34.639 grams of CuSO 4 5H 2 O in water 

 and dilute to 500 cc. 



(o) Alkaline tartrate solution. Dissolve 173 grams of Rochelle salts and 

 125 grams of potassium hydroxid in water and dilute to 500 cc. 



(2) GRAVIMETRIC METHOD FOR THE DETERMINATION OF DEXTROSE. 



Place 30 cc of the copper solution, 30 cc of the alkaline tartrate solution, 

 and 60 cc of water in a beaker and heat to boiling. Add 25 cc of the solution 

 of the material to be examined, which must be so prepared as not to contain 

 more than 0.250 gram of dextrose, and boil for two minutes. Filter imme- 

 diately through asbestos without diluting, and obtain the weight of copper by 



