588 



Van Name and Huff — 



by hydrolytic decomposition. 6 Drawe 7 introduced an 

 important improvement by substituting for the water a 

 25 per cent solution of sodium acetate. This expedient, 

 by keeping the concentration of hydrogen ion low, greatly 

 diminishes the rate of decomposition, so that frequent 

 removal of the liquid is unnecessary, and the care of the 

 apparatus is materially simplified. Still better results, 

 as our own experiments have demonstrated, can be 

 obtained by the use of a solution of sodium carbonate. 



Our apparatus, which is a modification of that of 

 Bansa, 8 is shown in the accompanying figure. It consists 



Fig. 1. 



of a cylindrical glass jar, conveniently about 5 inches in 

 diameter by 7 inches in height, provided with a flanged 

 cover of plaster of Paris, cast to shape. The phosphorus, 

 in the form of cylindrical sticks, twenty or more in num- 

 ber, is suspended in the liquid by glass rods, which pass 

 through holes drilled at regular intervals in the cover 

 and are held at the proper height by corks on the project- 

 ing ends. The fit of the rods in the holes is close enough 

 to prevent swinging. Each rod has a small knob or 

 enlargement at the lower end, and extends through the 

 whole length of the stick of phosphorus which it supports. 

 It is imbedded in the phosphorus by melting the latter in 



6 For measurements of the rate of this hydrolysis see Van Name and 

 Huff, this Journal, 45, 103, 1918. 



7 Ber. chem. Ges., 21, 3401, 1888. 



8 Zs. anorg. chem., 6, 128, 1894. 



