SANGER. — VOLATILE COMPOUNDS OF ARSENIC. 113 



frequently interrupted and delayed, but about two years ago, I arrived 

 rather reluctantly at results which seemed to show the improbability 

 of the formation of an arsenical gas, though the possibility was as 

 clear as ever. But the extension of bacteriological methods to the 

 investigation has thrown a new light on the matter, and during the 

 past year I have been able to satisfy myself of the correctness of the 

 investigations which have shown that a volatile arsenical compound 

 can be formed by action of certain moulds on organic matter contain- 

 ing arsenic. The nature of the compound is still unknown, and will 

 require extended investigation before it is determined; but it certainly 

 does not seem to be arseniuretted hydrogen, which was the compound 

 commonly supposed to be formed. 



Historical. 



The danger from arsenical colors in living rooms seems to have 

 been to some extent foreseen before cases of chronic poisoning actu- 

 ally arose, for an order of the Prussian government of January 12, 

 1815,* directed that the color should be rubbed from green walls when 

 wet. and not when dry. 



Gmelin,f in 1839, was the first to call attention to the danger from 

 arsenical wall papers, and considered that the arsenic might be volatil- 

 ized as some product of the fermentation of the organic matter with 

 which it was mixed. 



Riedehf in 1844, says that "air can take up arsenic acid and 

 hydrogen can form arseniuretted hydrogen." 



Von Basedow, § in 1846, considered that the arsenic might be liber- 

 ated in the form of kakodyl. He gives some cases of poisoning in 

 rooms painted with an arsenical green on a lime ground, and lays 

 stress on the peculiar garlic odor which he notices. This he com- 

 pares to the odor obtained by boiling arsenious oxide with acetic acid, 

 and says it is similar to that wbich arises from stuffed birds. The 

 occupants of the room noticed no such odor. Von Basedow notes 

 that the arsenic decreases in the paper by decay, but no analyses are 

 given in support of this assertion. 



Krahmer,|| in 1852, was the first to institute experiments to deter- 



* Krahmer, Deutsche Klinik, 1852, XLIII 481. 



t Ref. by Eulenberg, Die Lekre v. d. sr!,ddl. v. gift. Gasen, 1865, p. 413, to 

 Knrlsruher Zeitung, November, 1839. 

 J Kef. by Krahmer, lac. cit., to Ann. der Staatsarzneikunde, X. 407. 

 § Preuss Med. Zeitung, 1846, X. 43. 

 || Loc. cit. 



VOL. XXIX. (n. S. XXI.) 8 



