Lcmgenhan—The Arsenical Solutions. 
197 
metal, I thought it was probably Arsenic, which is known to abound 
very generally in coblat Ores.* Whilst I was intending to submit the 
drops to a more (p. 124) effectual examination, my good friend and your 
excellent Apothecary Mr. Hughes informed me, that he had made an 
analysis of the drops, and found them to be a solution of Arsenic. 
At first we gave the medicine cautiously,.... (This part of the letter 
deals with the dose and treatment of patients). In the Autumn of 
1784 it was almost constantly prescribed, and has ever since maintained 
its credit with us under a very great number of trials. 
At first we used a simple solution of Arsenicum album, one grain to 
each Ounce of distilled Water. The solution is facilitated by boiling for 
a minute to two in a florence Flask, or other glass Vessel, but long con¬ 
tinued boiling disposes it to precipitate again. After some time Mr. 
Baley (p. 125) added Nitre to the solution, by the direction of Mr. 
Hughes, to prevent the precipitation, which in the rapid consumption in 
the Hospital had hardly been observed to take place, but in the smaller 
demands of private practice seldom fails to happen. I should also men¬ 
tion that an ounce of alcohol has lately been added to twenty Ounces of 
the Solution, but I am doubtful of the propriety of this addition. 
(The. remainder of the letter deals with the dose and method of admin¬ 
istration) 
(Signed) (p. 127) Your obliged and faithful friend 
W. Withering. 
* See footnote to Thomas Wilson’s patent, p. 189 for chemical explanation. 
