192 



EXPEROIENT STATION. 



[Tan. 



spheres of the slow process. The copper acetate soluble results 

 are of iincertuin value. Filtered lime water, with .12 per cent, 

 calcium oxide, contained insufficient lime to prevent solution 

 of the arsenic. Ammonia dissolves Paris green and the normal 

 by-products concomitant with its manufacture, such as copper 

 arsenite, arsenous oxide, sodium sulfate and sodium acetate ; the 

 residue, .11 per cent, in case of the slow process green, was 

 organic and other insoluble materials. 



To ascertain the solvent action of various substances in solu- 

 tion on Paris green, a series of tests were conducted with the 

 slow process sample. The green in stoppered flasks was treated 

 with water and with solutions of the respective compounds at the 

 rate of 1 gram to 1,000 cubic centimeters for twenty-four hours 

 at laboratory temperature, with occasional agitation during the 

 working day. 



Solubility Tests, Slow Process Green. 



Solvent. 



Amount 



of Solvent 



in a 



Liter of 



Water 



(Grams). 



Soluble 



AS2O3 



(Per 



Cent.). 



Copper. 



Remarks. 



Distilled water 



Water saturated with CO2, 



Ammonium hydroxide (concen- 

 trated). 



Ammonium hydroxide (concen- 

 trated). 



Ammonium carbonate, . 



Ammonium carbonate, . 



Ammonium chloride. 



Ammonium nitrate. 



Ammonium nitrate, 



Ammonium nitrite solution, . 



Ammonium nitrite solution, . 



Ammonium sulfate, 



Sodium carbonate (anhydrous), 



Sodium bicarbonate. 



Sodium chloride, 



Sodium nitrate, 



Sodium nitrite, 



Sodium sulfate (anhydrous), . 



Boiling water, one hour. 



.84 



6.16 



.86 



13.49 



6.83 



55.93 



2.41 



2.03 



4.70 



.38 



.36 



4 20 



3 15 



.84 



.96 



.86 



.88 



1.67 



14.93 



None. 



Much. 



None. 



Much. 



Much. 



Excessive. 



Considerable. 



Trace. 



Much. 



Considerable. 



None. 



Very slight 



trace. 

 None. 



None. 



Ve r y slight 



trace. 

 Much. 



Residue darker green. 



Blue solution. 



Blue, nearly complete 

 solution. 



Change in color of res- 

 idue. 



' About 5 gallons of gas used, water pressure. 



