PURIFICATION OF ARSENICAL SULPHURIC ACID. 543 
paratively trifling. It has therefore been conjectured, that 
arsenic makes its way into the circulation before it terminates 
life, and acts by destroying the vitality of the blood, rendering 
it incapable of supporting the irritability of the heart, and 
the excitability of the brain and spinal cord. Precisely 
as does the poison of the rattlesnake, and other poisonous 
reptiles. 
That coma and paralysis are occasionally the consequence 
of remote action is proved by cases lately recorded in this 
Journal by Mr. Truckle, of Salisbury.] 
PURIFICATION OF ARSENICAL SULPHURIC ACID. 
L. A. Buchner* recommends the separation of arsenic 
from sulphuric acid as chloride of arsenic, which is volatilized 
at a temperature much below the boiling point of sulphuric 
acid, and is very readily formed by the joint reaction of 
arsenious acid with hydrochloric and sulphuric acids. 
The sulphuric acid to be purified is heated, and a moderate 
current of hydrochloric acid gas passed into it. The author 
states that the separation of arsenic by this method is perfect, 
and easily effected, even when it amounts to considerably 
more than is usually met with in the sulphuric acid obtained 
from pyrites. It would therefore have the advantage over the 
method of distillation, which is imperfect, because the tem- 
perature at which arsenious acid volatilizes is too near the 
boiling point of sulphuric acid, and also, over the method of 
precipitation as sulphide of arsenic, which is extremely 
operose. Moreover, it may perhaps have the merit of ensuring 
the separation of the nitrous acid usually present in crude 
sulphuric acid. — Ibid, 
* ‘Neues Repertorium fur Pharmacief No. 3, 1855. 
