THE INDIVIDUAL GROUPS OF PROTEINS 



513 



The apparatus is designed to effect an analysis in presence of aqueous 

 vapour and in the presence of nitrogen contained in the capillary tubes 

 between the gas burette and the absorption bulbs. The nitrogen prevents 

 the potash and pyrogallol from entering the gas burette, the potash and 



FIG. 73. 



pyrogallol bulbs having marks upon their limbs so that the volrme of gas 

 can always be made the same by making the liquids stand at the marks. 

 The control tube (C) and its connection with the potash bulb and reservoir 

 (R) allows of the volume of air in it and the connections being kept constant 

 to the mark (N) by adjusting the height of the liquid in R. 



