90 THE CHEMICAL CONSTITUTION OF THE PROTEINS 



The whole apparatus was filled with nitric oxide, and this gas was used 

 for washing the evolved nitrogen into the eudiometer ; the excess 

 of nitric oxide was then removed with permanganate contained in a 

 Hempel pipette. 



FIG. 2. 

 From J. Biol. Chem., 1912, 12, 278. 



A modified form of apparatus was devised by Klein [1911] and 

 this form of apparatus, greatly improved, was adopted by Van Slyke 

 [1912, i]. It has entirely displaced the older form of apparatus, and 

 is shown in figs. 2 and 3, the latter figure showing all the parts of the 

 apparatus assembled for use upon a fixed stand. The parts are more 

 frequently assembled on a stand which is movable. 



The apparatus consists of the deaminising bulb D of 40-45 c.c. 

 capacity for the interaction of the nitrous acid and the solution of the 

 amino substance. It has a mark at 20 c.c. Connected with this 

 vessel, are 



