598 POISONS : THEIR EFFECTS AND DETECTION. [§ JJI. 
possesses many advantages. The methyl arsenite is easily broken up 
by treatment with an alkali. The distillate can be made up to a known 
volume, and a portion submitted to the Gutzeit test, and arsenic, if 
present in sufficient quantity, precipitated by SH 2 . 
There are various other methods of distilling off arsenic in a volatile 
form, e.g .:—Treatment of the substance with concentrated hydrochloric 
acid, hydrazine sulphate, and bromide of potassium, and distilling the 
arsenic chloride into water (Bohrisch and Kurscher, Pharm. Zentr., 1911), 
distillation by means of hydrochloric acid, and reduction of any arsenic 
compounds by the addition of cuprous chloride (Roark and M‘Donnell, 
J. Ind. Eng. Ghem., 1916). 
It is, however, not essential to use any distillation process in certain 
cases : chloride of arsenic in concentrated sulphuric acid, for example, 
as formed by adding pure common salt or hydrochloric acid to the con¬ 
tents of the Kjeldahl flask in the process detailed p.597, can be extracted by 
benzene or chloroform. On washing the chloroform with water in a separat¬ 
ing funnel, first concentrating the volatile solvent to a few c.c., the whole 
of the arsenic passes into the water and may be identified and estimated. 
§ 771. Distribution of Arsenic in the Body.— In searching for arsenic 
in the fluids or tissues of the body, the analyst is generally at the mercy 
of the pathologist, and sometimes the work of the chemist leads to a 
negative result, solely from not having the proper organ sent to him. 
Brodie long ago stated that when arsenious acid had been given in solu¬ 
tion to any animal capable of vomiting, no arsenic could be detected in the 
stomach; this statement is too absolute, but in the majority of cases true. 
In all cases the chemist should have portions of the brain, spinal 
cord, liver, kidneys, lungs, and muscular tissue, as well as the stomach 
and its contents. 
According to the experiments of Scolosuboff, 1 arsenic is generally 
greatest in the marrow, then in the brain, next in the liver, and least in 
the muscles, the following being the proportion if muscle be taken as 1 :— 
Muscles 
Liver 
Brain 
Spinal marrow 
1 
10-8 
36- 5 
37- 3 
But Ludwig’s 2 experiments and conclusions are entirely opposed 
to this, since both in acute and chronic cases he found as follows (per 
cent. As 2 0 3 ) :— 
Brain 
Liver 
Kidney- 
Muscle 
•0002 
•001 
•0004 
•00025 
1 Bull. Boc. Chim. (2), xxiv. 124. 
2 “ Ueber die Verhaltung des Arsens im thierischen Organismus nach Einver- 
leibung von arseniger Saure,” Med. Jahrbuch, 1880. 
