XXX 



Remedial Measures and Insecticides. 



or chalk is added to this sizing, with or without the addition of 

 lampblack. A few make use of the mucilaginous juice of the 

 common cactus {Opuntia Etigebnannt) for this purpose. To 

 obtain this, the cactus leaves or stems are cut or broken up into 

 pieces, thrown into a barrel, and covered with water, after which 

 they are allowed to soak for three or four days. The liquid 

 portion is then drawn off, and is ready for use without further 

 preparation. Tents which I saw that had been prepared with this 

 substance were to all appearances as air-tight and pliable as when 

 prepared in any other manner.' 



For the oiling, Mr. Lounsbury recommends a mixture of four 

 parts boiled linseed oil to one part turpentine. The cloth should 

 be first well wetted with water, and the mixture spread lightly over 

 the surface with a brush. A thin coating is found to be sufficient. 

 Mr. Lounsbury has since informed me that he now uses, with 

 completely satisfactory results, tents made of cloth merely shrunk 

 in water, without any subsequent oiling. Such tents are, of course, 

 much lighter and more easy to manipulate. 



Mr. Coquillet gives the annexed table, showing the quantities 

 of chemicals required for different-sized trees. 



Mr. Lounsbury, after practical experience at the Cape, pub- 

 lishes the following figures, from which it appears that he found 

 smaller quantities sufficient. This is, doubtless, due to difference 



