cxcni 



given in our Transactions, some years ago, reasons for believing 

 that the Mastodon had been contemporaneous w^ith man in Mis- 

 souri ; and though Prof. Dana had shown that Dr. Koch was not 

 a scientific and reliable observer, he did not venture to deny that 

 the fact might be so. 



A paper by Prof. G. C. Broadhead, on -'The Rocky Mountain 

 Locust and the Season of 1875," was read, and referred to the 

 Committee on Publication. 



Mr. Riley made some remarks on the use of Paris green as 

 an insecticide, and cited some recent experiments by Dr. R. C. 

 Kedzie, of the Michigan Agricultural College, which fully bore 

 out his (Riley's) own previous conclusions and advice, and from 

 which he drew the following : 



1. Paris green that has been four months in the soil no longer 

 remains as such, but passes into some less soluble state, and is 

 unaffected by the ordinary solvents of the soil. 



2. When applied in small quantities, such as alone are neces- 

 sary in destroying injurious insects, it does not affect the health 

 of the plant. 



3. The power of the soil to hold arsenious acid and arsenites 

 in insoluble form will prevent water from becoming poisoned, 

 unless the green be used in excess of any requirement as an insect 

 destroyer. 



He referred to other "potato-bug" poisons, especially one made 

 at the Lodi (N. J.) Chemical Works, which analysis shows to be 

 half salt, half arsenic (arsenate of copper). It cost one dollar a 

 pound, was no cheaper than Paris green, and was more dangerous 

 on account of its color, which rendered it liable to be confounded 

 with common salt. 



January 3, 1876. 

 Albert Todd, Vice President, in the chair. 



Nineteen members present. 



Mr. Riley, in accordance with instructions at the previous 

 meeting, reported that he had taken measures to have an authori- 

 tative report of the Proceedings published in The Western. Mr. 

 L. B. V. Dixon, with the assistance of the Secretary, will prepare 

 such a report and the matter will be at once set in type, so that 

 galley proofs may be had on application to the former gentleman. 



