Pomona College Journal of Entomology 389 



It will be seen that the cost is of enough importance to warrant the buying 

 of the sodium cyanide, providing that it does as good work and will not 

 burn the fruit or injure the foliage. With us it is just as good as the potassium 

 without the injurious qualities and with the additional advantage that it does 

 not burn damp and cold foliage and fruit as readily as does the potassium 

 cyanide. 



I understand that the "American" sodium cyanide is much cheaper than 

 the imported brand under discussion. It corresponds more to the potassium 

 cyanide in the amount of available hydrocyanic acid gas available, being what is 

 known as 98-100 per cent. Mr. Woglum made some tests regarding this 

 chemical with the result that he pronounced it unfit for fumigation purposes. 

 Since then Mr. C. E. McFadden, who has had a great deal of fumigation 

 experience in the most practical way, gave this cyanide a trial. He told the 

 writer that he got excellent results with it and I remember quite distinctly 

 that he expressed his desire to get this form of sodium cyanide last fall 

 in place of the European brand. From our experience with the sodium, 

 I can see no reason why the cheaper quality will not do the work. It is at 

 least worth trying, and I think that every progressive fruit grower should 

 look into the matter. The cyanide outlook is not at all encouraging. If 

 a cheaper form can be obtained, so much cheaper as the form under dis- 

 cussion, it should be given a thorough test. Certainly I shall make experi- 

 ments with it as soon as any quantity of it may be had. 



The one objection to sodium cyanide, not mentioned above, is the formation 

 of the sodium or alkali salt from the residue. The residue of the potassium 

 cyanide amounts to several dollars worth of good fertilizer to a ton, which is 

 no little item in a large orchard, while the salt from the sodium cyanide 

 has a negative value and is a distinctly harmful product. It might be ad- 

 visable to empty the residue in a waste tank and dump it outside of the 

 orchards because of this, but our experience with the cyanide, like that with 

 the nitrate of lime, is so limited as to make any remedial remarks seem un- 

 necessary. 



