74 



CALIFORNIA CITRUS CULTURE. 



Acid Container. For ordinary work a three, five or ten-gallon 

 earthenware jar is sufficient. A lead lid for the top and a three fourths 

 inch iron pipe inserted through a hole in the side near the bottom with 

 a piece of pure rubber tubing six inches long and closed by a clamp 

 is a cheap and practical device. Lead-lined tanks are more durable, 

 but also much more expensive. 



Water Tank. As there is three times as much water used as acid 

 the water tank must necessarily be larger. For a hand cart a pickle 

 keg is excellent, while a twenty-five or fifty-gallon barrel may be neces- 

 sary for a large wagon. An extension pipe and faucet furnish the 

 outlet which should be near that of the acid tank. 



Graduates. The quantity of acid and water used depends entirely 

 upon the amount of cyanide required for a dose. For every ounce of 

 potassium cyanide one fluid ounce of sulphuric acid and three fluid 



FIG. 50. A cheap and 



ind chemical cart. (Photo by Vaile.) 



ounces of water are used, while for sodium cyanide one and a half 

 fluid ounces of sulphuric acid and two fluid ounces of water are used. 

 As this is a fixed ratio in each case, graduates have been made to 

 measure out the exact amount of the liquid required in the terms of the 

 number of ounces of cyanide ; for instance, if it required twelve ounces 

 of sodium cyanide for a dose the acid graduate is so scaled that it would 

 be filled to the twelve ounce line, which would mean eighteen liquid 

 ounces and the water graduate to the twelve ounce line, which would 

 be twenty-four liquid ounces. Such a scheme makes it unnecessary to 

 make mental calculations and thus avoids mistakes. 



