The following gentlemen were unanimously elected cor- 

 responding members of the Society : 



Edward Doubleday, Esq., of Epping, England. 

 Francis Archer, Esq., President of Geological Society, Liver- 

 pool. 



Mr. Richard Soule, Jr. was elected a member. 

 Adjourned, 



T. B. Sec. pro tern. 



April 21, 1841. 



The President in the Chair. 



Eleven members present. 



Dr. Gray made some remarks on a paper in the last num- 

 ber of Silliman's Journal " On detecting arsenic in the ani- 

 mal body," by Dr. J. Lawrence Smith. 



He indicated an imperfection in the statement of the experi- 

 ments of Orfila for the detection of arsenic in the peroxide of iron, 

 in its not being stated, with sufficient clearness, whether the pro- 

 cesses pursued would discover arsenic if any existed. The reader 

 may infer this; but it should have been distinctly stated. The 

 hyd rated oxide of iron, which is usually employed as an antidote 

 to arsenic, does sometimes contain a small portion of arsenic. This 

 the writer states is not hurtful, " being slowly absorbed and elimi- 

 nated by the urine." Dr. Gay expressed his doubts whether this 

 process would take place. It requires strong evidence, which it is 

 not stated has been obtained. The writer says : " little difficulty 

 will be found in procuring zinc of the necessary purity to be used 

 in Marsh's apparatus." Dr. Gay remarks on this, that it is both 

 highly important and extremely difficult to procure zinc and other 

 materials for reagents which are themselves entirely free from 

 arsenic. In zinc, for instance, arsenic may be contained in atoms 

 in certain parts of the mass, while other parts may be wholly free 

 from it. Therefore testing one portion will not give grounds for a 

 certain inference with regard to another portion. Dr. G. spoke of 

 Marsh's apparatus as ingenious, but liable to certain objections, 



