SANGER. — CHRONTC ARSENICAL POISONING. 155 



criticism from the method of analysis used. In one case, the wall 

 papers were in several layers, all containing arsenic, the inner more 

 than the outer. The reagents were all tested by a run of 45 minutes, 

 but gave no mirror resembling arsenic. In the first case, four litres 

 of urine were treated with potassic chlorate and hydrochloric acid, but, 

 as the destruction of the organic matter was slow, Schneider's method 

 of distillation with salt and sulphuric acid was resorted to, though no 

 attempt was made, apparently, to reduce the arsenic acid before dis- 

 tillation. The distillate was precipitated by sulphuretted hydrogen, 

 and the precipitate dissolved in ammonia. One half of this solution 

 was evaporated, and the residue examined, accordiug to Fresenius 

 and Babo, by mixing with sodic carbonate and potassic cyanide, and 

 heating in a stream of carbon dioxide. A white mirror was obtained, 

 which on refusion and reheating gave a dark mirror, partially soluble 

 in sodic hypochlorite. In another case, Morner obtained a " large " 

 mirror. The patient iu whose urine this was found weut into a room 

 containing no arsenic, and one month later there was no arsenic in 

 the urine. Two other cases gave " smaller " mirrors, another a 

 " doubtful," and in one case there was none. In the urine of people 

 living in rooms containing no arsenic, there was no arsenic found. 

 All the analyses after the first were made by Schneider's method 

 directly. 



One cannot help, on reading Morner's paper, distrusting the results 

 obtained, as the course of analysis would not only allow arsenic to 

 creep in, but might result in the loss of arsenic, if not carefully con- 

 ducted. As W. Fresenius* has shown, the Fresenius-Babo method 

 is capable of very delicate work in careful hands, but, in general, it 

 does not give as good results as the Berzelius-Marsh. 



Jolin,f in 1880, gives the case of a man occupying a badly venti- 

 lated room with an arsenical wall paper, who suffered from recurrent 

 gastric catarrh, conjunctivitis, and great weariness. The urine was 

 treated with potassic chlorate and hydrochloric acid, and evaporated 

 to dryness on the water bath. Potassic nitrate was then added, and 

 the mass warmed with sulphuric acid until nitrous fumes ceased. 

 Into the solution was then passed sulphuretted hydrogen (from calcic 

 sulphide and hydrochloric acid), and the resulting precipitate event- 

 ually introduced into the Marsh apparatus. A mirror was obtained 

 2 cm. long, equally translucent over the entire length, and was 

 judged to be between 0.05 and 0.01 mgr. The reagents were care- 



* Fresen. Zeitschr., XX. 522. t Hygeia, Stockholm, XLII. 235. 



