﻿Aug., 1858.] 



ELLIOTT SOCIETY. 



287 



A letter was read from Dr. E. Brown-Sequard, accepting his 

 election as Corresponding Member. 



A communication was read from W. Sharswood, Esq., 

 describing an expeditious method of preparing an antidote for 

 Arsenious Acid. 



Dr. J. F. M. Geddings. 



Bear Sir — Since I have an occasion for addressing you, it may 

 not be out of place to preface my remarks by an account of the 

 new Antidote for Arsenious Acid, the original paper on which is 

 ■ sent to Europe. 



The only antidote for Arsenious Acid heretofore known, (ex- 

 cepting the less important one, Caustic Magnesia,) is the hydrated 

 sesquioxide of iron, the ferrugo of the Edinburgh Pharmacopaea. 

 To prepare this it is recommended to precipitate protosulphate of 

 iron, by an alkaline carbonate, the precipitated protocarbonate, 

 during the process of washing and drying, loses its carbonic acid, 

 and attracts oxygen, becoming hydrated sesquioxide of iron. 



It is well known that to administer the above antidote, con- 

 siderable time is required for its preparation, and, with the excep- 

 tion of large towns where the substance is kept ready prepared on 

 the apothecary's shelves, the life of a patient must be often 

 sacrificed to the time necessary for its formation ; and aside from 

 even its being ready prepared, it is well known that it is only in 

 its recently precipitated condition that it is most active. 



The antidote to which I refer while depending upon the same 

 principles, is characterized by facility and speed of prepa- 

 ration, and at the same time possessing within itself a cathartic 

 principle. 



To prepare this we have merely to take a solution of the proto- 

 sulphate of iron, and after having oxydized the iron with a few drops 

 of nitric acid, precipitate the oxide with caustic magnesia, when 

 the result is a precipitate of hydrated sesquioxide of iron, com- 

 bined with sulphate of magnesia or epsom salts. 



In this way we have immediately the sesquioxide of iron 

 together with sulphate magnesia. 



It will also be seen that the rapidity with which this is formed, 

 renders it unnecessary to be made before the time of use, which is 

 a great disadvantage with the ordinary antidote, from the fact of 

 its being kept for months, if not years, whereas it has been shown 

 that it is only in its recent condition that it is most active. 



