FIFTH MEETING. 



ROYAL INSTITUTION, December 16th, 1844. 



Rev. Dr. Tattershall, Sen., Vice-President, in the Chair. 



Mr. Balman was admitted a Member of the Society. 



THE PAPER FOR THE EVENING WAS, 

 " ON THE MODE OF DETECTING MINUTE QUANTITIES OF 

 ARSENIC, AND OF DISTINGUISHING IT FROM OTHER 

 METALS, ESPECIALLY IN REFERENCE TO MEDICO-LEGAL 

 INQUIRIES."— By Dr. Brett. 



The object of the present short paper is to lay before the 

 Society, what appear to me to be the most exact methods, 

 at present known, for demonstrating the presence of arsenic, 

 especially in small quantities, and also the best modes of 

 distinguishing it from other metallic bodies with which it 

 might be confounded. The medico-legal analyst is placed 

 in a very different position from the general analyst ; from the 

 fact, that the former is called upon for a more rigid demon- 

 stration of the truth of the results at which he arrives in his 

 experiments, than the latter. That sort of moral certainty, 

 or conviction, which may satisfy a person of the existence 

 of a certain substance (perhaps in excessively minute quan- 

 tity,) in a common case of chemical analysis, will not 

 suffice in a case where the question of life or death may 

 be involved in the statement of the analyst. The greatest 



