'^^ LII. On the Combination of Arsenious Acid with Albumeni^^^^ 

 -oiq ^ijouiib ^2^ Thornton J. Herapath, Esq,"^ > >K>iiq«^6Ati 



jVrOT a little controversy has recently occurred amongst cKe- 

 i-^ mists with regard to the nature of the combination which 

 is stated to take place between arsenious acid and albumen. 

 According to Prof. Liebigf, these two bodies combine in atomic 

 proportions, and it is owing, he says, to this circumstance that the 

 vitality of the organs is destroyed in cases of arsenical poisoning. 

 The same opinion, it seems, is entertained by Dr. Sheridan Mus- 

 pratt of Liverpool, who has lately published some results J which 

 certainly appear to establish the truth of the hypothesis. Other 

 chemists, on the contrary, say that this statement of Liebig^s is 

 founded on error — that arsenious acid does not, under any cir- 

 cumstances, form a true chemical combination with albumen, 

 and is only separated by the latter substance from its solutions 

 by a species of mechanical action ; that is to say, somewhat in the 

 same manner, perhaps, as iodine and many vegeto-alkaloids are 

 well known to be absorbed and extracted from their solutions by 

 animal charcoal. In evidence, they adduce the results of Mr. 

 Edv/ards^s experiments, an account of which was published some 

 few months back in the Transactions of the Chemical Society of 

 London §. According to this latter experimentalist, the whole 

 of the arsenious acid may be readily extracted from the compound 

 by means of boiling water, provided the operator takes care 

 " thoroughly to break up the mechanical network of the coagu- 

 late " (I adopt his own expression), by trituration with a pestle 

 ^nd mortar. 



'^,, A short time ago, my attention was drawn to the subject by 

 my father. Prof. W. Herapath, who desired me to repeat the ex- 

 periments above referred to, with the view, if possible, of deciding 

 the question, as it was one which he considered of much interest, 

 in consequence of its bearings on Toxicology. I accordingly did 

 so. My results may be summed up as follows. 



Experiment I. — 499 grains of the glairy albumen of eggs 

 were taken and intimately mixed, by long-continued trituration, 

 with 3-0 grs. of arsenious acid ; the latter having been previously 

 dissolved in a quantity of water sufficient to effect a perfect solu- 

 tion. The mixture was then coagulated by heat, and afterwards 

 carefully evaporated to dryness in a water-bath. The yellowish 

 residue thus obtained was reduced to a very fine powder in a 

 mortar, and repeatedly digested, for sexei;al, hours to^et)|er,,iu 



* Communicated by the Author. - v. ^ > ... , . 



t Organic Chemistry, part 2. chap. xiv. p. 358. , 



X Quart. Journ. of the Chem. Soc. of London, No. xiv. p. 178. "^^^ 

 § Ibid. No. ix. p. 14. .of.T^r«'MMJp 



