330 



THE MO^"l'lll.^• BULLETIN. 



Both of the cyanides are good and reliable, and the deciding features 

 \\ ill |)r()l)ab]y always be the supply avai]al)le and the price. 



Sulphuric Acid. — Fumigating sulphuric acid has a specific gravity 

 of about (i6 degrees Baume and often containing traces of nitric acid 

 and arsenic, lead or zinc. It has been the current belief that especially 

 nitric acid caused the burning of the fruit and foliage so often the 

 results of fumigating work, but R. S. Woglum in Bull. No. 90, Part I, 

 page 42, U. S. Dept. Agrcl. Bureau, Entomology, states that this is an 

 erroneous ])elief. It should always be the aim of every fruit grower to 

 get good grades of sulphuric acid, which is not at all difficult at the 

 l>resent time. 



CHEMICAL PROPORTIONS. 

 Potassium Cyanide: 



Potassium c.\;uiide 1 ounce. 



Suliiluu'ic acid__^, 1_ : 1 fluid ounce. 



\Vater .iz 3 fluid ounces. 



Sodium Cyanide: 



Sodium cyanide_! 1 ounce. 



Sulphuric acid — ^>»^ li fluid ounces. 



Water JV .2 fluid ounces. 



METHODS OF PROCEDURE. 



For an outfit of thirty or thirty-five tents five men arc re([uired to 

 operate to an advantage. Two men pull the tents and Idck in the edge^ 

 around the bottom. One man, the taper, takes the measiirements of the 

 tree and calls them off to the man who weighs out the cy-anide. After 

 determining the dosage this man also empties the generators from the 

 row just finished and has them ready for the next trees- by the time the 

 chemical cart arrives. The man who weighs the cyanide determines the 

 dose on the schedule from the measurements called out by the man who 

 measures the tents. The cyanide man. also lifts :tlie Tent-so- that the 

 last man who measures out the acid and water in the generators may 

 place them well under the tree, after which the cyanide is added. In 

 no case should the acid man touch the tents! While the chemical men 

 are dosing one tree the taper is getting the measurements for the next 

 tree ready in advance. In brief, the procedure is as follows: putting 

 the tents over the trees, measuring and dosing. The string of thirty 

 tents can be easily dosed within forty-five minutes or an hour. Methods 

 of procedure vary considerably, the above being general. 



For extra large trees a special tent-hoisting apparatus (Fig. 316) 

 has been devised by Mr. C. E. McFadden, with which a 70 or 80-foot 

 tent can be easily and quickly put over the largest citrus trees. 



