PROPORTION OF CHEMICALS. 



37 



3 parts. The reactions were accomplished in 2-gallon earthenware 

 fumigating vessels in a room where the air was moderately quiet. 

 The temperature of the gas was taken at the mouth of the vessels. 



Table III.— Experiment to determine the temperature of the gas resulting from large and 



small dosages. 



Amount of chemicals used. 



Cyanic! . i Acid. | Water. 



OuTices. 

 3 

 6 



Ounces. Ounces. 



Time 

 after gen- 

 eration 

 when 

 tempera- 

 ture of 

 gas is 

 highest. 



°F. 

 73 



S6 

 92 

 90 

 95 

 98 

 99 

 106 



An examination of this table shows that the temperature of the 

 escaping gas increases somewhat as the dosages become larger. 

 Hence if heated gas is more injurious than cooler gas, we would ex- 

 pect more burning as a result of the increased dosages. This is 

 exactly what does happen to some extent in field operations. It is 

 interesting to note that thje highest temperature of the acid-water 

 mixture occurs about one-half minute after the mixing takes place. 

 The highest temperature of the hydrocyanic-acid gas occurs about 

 one-half minute after the generation commences, and then the tem- 

 perature of the gas rapidly decreases during two to two and one-half 

 minutes, at the end of which time most of the gas has been evolved. 

 At the expiration of from three to five minutes the generation of gas 

 has practically ceased. 



THE EFFECT OF DIFFERENT PROPORTIONS OF WATER ON THE AMOUNT OP AVAILABLE 



HYDROCYANIC-ACID GA.S. 



In the course of this investigation an experiment was made to deter- 

 mine the amount of hydrocyanic-acid gas available when generated 

 with different proportions of water. The results as determined by the 

 Bureau of Chemistry of this Department are given in the accompa- 

 nying chart (fig. 13). 



In these experiments commercial sulphuric acid, 66° Baume or 

 92.77 per cent pure, and potassium cyanid 97.12 per cent pure were 

 used. Three ounces (fluid) of sulphuric acid and 3 ounces (avoirdu- 

 pois) of potassium cyanid were employed in each experiment, and 

 3, 6, 9, 12, 15, 18, 21, and 24 ounces, respectively, of water were used 

 in the different experiments. 



