261 



used in twice the quantity of the emulsifying agent to obtain the best 

 results. In a recent pleasant visit to Lansing 1 drew Mr. Cook's atten- 

 tion to this fact in conjunction with his claim of having first recom- 

 mended the emulsion in a paper published in the Bulletin of the Michi- 

 gan State Board of Agriculture for 1878. This paper referred to the 

 mechanical mixture of soapsuds and kerosene used by others years 

 before. Upon Mr. Cook's showing me a vial of this so-called emulsion 

 it confirmed what I have said, in that the oil was entirely separated 

 from the soap." 



Mr. Gillette remarked, in confirmation of what was said by Mr. Riley, 

 that he did not know what a kerosene emulsion was until he learned to 

 make it by the Hubbard formula at Ames, Iowa. 



Mr. W. B. Alwood said he had spoken of the best method of prepar- 

 ing the emulsion in Bulletin 14 of the Division of Entomology. Mr. Al- 

 wood also spoke of kerosene emulsion as a new remedy for the Horn 

 Fly. An emulsion made according to the Hubbard formula, and diluted 

 with 10 parts of water, he found amply strong for the destruction of the 

 flies. Mr. J. B. Smith said he had found a dilution of 1 to 12 to be 

 sufficiently strong for most insects, and 1 to 15 was strong enough for 

 plant lice. For the destruction of scale insects he had found it neces- 

 sary to use the emulsion as strong as 1 to 10 with water. Mr. Smith 

 said that the mixture should be boiling hot when emulsified, and then 

 if kept in a cool place, free from sudden jars, it would last for a year or 

 more without separating. He had found that a high temperature or 

 sudden jar would cause the oil to separate and rise to the surface. 



In regard to the combination of lime and London purple in water 

 mixtures Mr. Smith had found that when thus mixed no arsenic would 

 be deposited on copper, but if no lime was put in the water with the 

 Loudon purple there would be an abundant deposit, showing that the 

 lime actually has the effect to hold the arsenic in an insoluble condi- 

 tion. 



Mr. Alwood stated that he had found the kerosene emulsion effectual 

 in destroying plant lice when diluted with 20 or even 25 parts of water. 



The next paper was by Mr. C. M. Weed on the life history of Baris 

 confinis Lee. Mr. Weed stated that he had found this insect abundant 

 in both the larval and pupa state in the stems of the Spanish needle, 

 Bidens frondosa. This paper is to be published elsewhere, and no ab- 

 stract has been furnished for this report. 



The committee adjourned to meet again in the evening. 



EVENING SESSION. 



The committee was called to order by the chairman, S. A. Forbes. 

 The first paper was by Mr. G. F. Atkinson, on a new root-rot disease 

 of cotton. 



