80 



A microscopical examination of the substance prepared by Professor Cook's formula 

 showed the buttery mass above to be apparently a good emulsion, and the jelly-like 

 mass below to contain scarcely any traces of oil globules. A similar examination of 

 the second preparation showed in different samples as usual a uniform emulsion. 



I conclude that in the first case I formed an emulsion, that is, the oil was broken 

 into minute globules and these coated with a film of soapsuds so that they did not 

 coalesce, but that there were such an excess of soapsuds that the emulsion separated 

 therefrom and rose to the top. 



It is evident, I think, at sight that the preferable preparation is the one which 

 combines the proportions so that no excess of either ingredient results, for, as indicated, 

 the hardening of the thick soapsuds results in clots and these interfere with spraying, 

 while to skim oflf the emulsion and leave the mass below is a useless labor and loss of 

 material. 



In the Riley-Hubbard formula we have evidently the exact proportions carefully 

 determined, and I feel obliged to recommend this formula when giving advice to those 

 wishing instructions as to preparation of kerosene emulsion. 



A NOTE ON SILK CULTURE. 



BY PAUL WALLACE, LOS ANGELES, CAL. 



[Secretary's Abstract.] 



The author reviewed the attempts which have been made to raise Silkworms in this 

 countrv, and stated that they had proven the entire adaptability of the United States to 

 this industry. He stated that all that was needed to make it a success was either a 

 bounty paid by the Government or an import duty upon raw silk, but to his own personal 

 knowledge attempts in this direction were thwarted by the work of large silk manufac- 

 turers who were bitterly opposed to the establishment of silk culture in America. He 

 urged that the Association should use its best efforts to foster a popular sentiment an- 

 tagonistic to such efforts on the part of the manufacturers of silk. 



Mr. Lintner, in discussing this paper, contended that there is no question as to our 

 ability to raise good silk, but that it will not pay. He spoke particularly of the work of 

 the division of entomology in experimenting in this direction. 



NOTES ON A FEW BORERS. 



BY G. C. DAVIS, AGRICULTURAL COLLEGE, MICHIGAN. 



If we go on the principle that " every little helps," even though it be slight and 

 incomplete, then perhaps a few notes incidentally picked up on our forest borers may be 

 of some utility at this time. Dr. Packard's work on forest insects, so recently is-ued, is 

 of inestimable value to the working entomologist, but by the reporting of the few obser- 

 vations we happen to make while at our other work we can make the volume still more 

 complete and helpful. Perhaps the habits of some of these species may already be 

 known, but as they have not been specially reported in this work, reference is here made 

 to them. 



From the maple was reared the Cerambycid borer Acanthoderes decipiens. It was 

 found as a pupa in the rude chip case just under the bark. The cylindrical burrow made 

 in its exit extended well in toward the heart of the tree and through quite sound wood. 



Another Cerambycid, Leptura proxima, was found quite numerous in blocks of hard 

 maple sawed from the tree the winter previous. The grubs were quite large, and it was 



