100 



HYDROCYANIC-ACID GAS FUMIGATION IN CALIFORNIA. 



except, of course, on a small scale, and provision was made for the 

 collection of the liberated hydrocyanic acid that it might be quanti- 

 tatively determined. Figure 13 shows a cut of the apparatus employed 

 for this purpose. On account of the inability to control the large 

 volume of gas which is so rapidly generated when the solid cyanid is 

 all added to the acid at one time (as is done in actual practice) it was 

 necessary to add it slowly, and in order to do this the charge was dis- 

 solved in water. 



DESCRIPTION OF APPARATUS. 



"A" is a flask of about 100 cc capacity into which the chemicals 

 are placed for the generation of the hydrocyanic-acid gas; "B," 



Fig. 13. — Apparatus used in the decomposition of cyanids and collection of the liberated hydrocyanic- 

 acid gas. (Original.) 



"C," and "D" are DrechseFs gas wash bottles, and into each is put 

 about 100 cc of a dilute solution of potassium hydrate to absorb the 

 gas. Bottle "F" contains a potassium hydrate solution to free the 

 air that is drawn through from carbon dioxid, which decomposes 

 cyanids in solution when passed through them. "E" is a condenser 

 containing cold water to cool the gases before reaching "B" and 

 thus prevent heating the solution in "B," which would cause decom- 

 position of the potassium cyanid formed. 



DETAILS OF MANIPULATION. 



To "A" add 10 cc of water, then 10 cc of concentrated sulphuric 

 acid, after which add immediately to the separatory funnel 5 grams 



