329 
CHEMICAL NOTES ON ATOXYL 
BY 
M. NIERENSTEIN. Ph.D. 
From the Runcorn Research Laboratories of the Liverpool School 
of Tropical Medicine 
(Received for publication 9 December, 1908; 
The following .s a record of chemical observations made during 
the last two and a half years whilst working on the chemical 
constitution and physiological action of Atoxyl. 
Water of crystallisation.-T\.^ differences in amount o 
arsenic found in samples of Atoxyl due to the differences in 
of crystallisation (Moore. Nierenstein and Todd.^ 
Bertheim ,2 and others), suggested an exact estimation o 
ofcrystallisation and‘adhering moisture/ Experiments ^ P 
that Atoxyl contains from one half to one and a a 
adhering moisture, and x^ricsrs adhering 
tion. Further observations showed that A ^ y ..^rpntrated 
moisture in about five weeks when standing over c 
sulphuric acid ; after this time no further loss o weig ^ 
in L course of six months. It contarns, ‘hen, two molecu es of wate 
oferystaursation wh.ch are only lost on dryrng ,, 
i6o» C. Atoxyl, after having been kept over sulphuric acid 
least five weeks, has, therefore, the formula : 
H.N.C.H.'AsO<«H, + a H,A corresponding to a 3 - 88 % arsenic. 
rheretore, in order to be kept 
m a given dose of Atoxyl, it IS ad\ isa ^Hd for at least five 
in a dark desiccator over concentrated su p uric account 
weeks before use. The dark desiccator ough^t to 
of the decomposition of Atoxyl solutions when exposed 
^“letime. j. Atoxvl manufactured 
Inorganic ^'"‘^,'J;ke“charlottenberg, have been 
By the Vereinigte Chemische werke, 
