REVIEWS — Taylor's treatise on poisons. 287 



The detection of poisons by chemical means having of late years 

 attracted the attention of some of the most distinguished chemists, 

 it was natural to expect that in the new edition (carefully and accur- 

 ately reprinted by Messrs. Lea and Blanchard,) every attention would 

 be paid to such improvements as had been made and had stood the 

 test of experience, and that such new processes as had been recom- 

 mended by competent authorities would be here reproduced, and if 

 open to objection would be discussed in a spirit of impartial enquiry ; 

 in short, that the work in scientific accuracy would keep pace with 

 the time. Such, however, does not appear to be the case as regards 

 the only portion of the work which we have as yet had time to ex- 

 amine, and in the following pages we intend to draw attention to a 

 few matters connected with the detection of arsenic, and more espec- 

 ially to the very off-hand manner in which Dr. Taylor dismisses the 

 method of extracting that substance from organic tissues, which 

 originally proposed by Duflos, has received the sanction of such men 

 as Presenius, Otto, and Wohler, which is undoubtedly the best at 

 present known both as regards ease and accuracy, and which we have 

 not the slightest doubt Dr. Taylor himself would adopt, could he be 

 induced to submit it to the test of experiment. 



The following quotations from Dr. Taylor's work, page 365 et seq., 

 will serve as a basis for some remarks on the subject of the extrac- 

 tion of arsenic from organic tissues : — " MM. Danger and Flandin 

 recommended the complete carbonization of the organic matter by 

 heating it in a quantity of strong sulphuric acid (proved to be free 

 from arsenic) equal to about one-third of the weight. It thus forms 

 a tarry looking mixture, which should be brought to dryness. The 

 vapours evolved during this operation are of the most offensive and 

 persistent description." 



"• If sulphuric acid can be obtained pure, there is no doubt that 

 this is the best mode of carbonizing organic matter. The carbona- 

 ceous mass should not be too strongly heated, or, as pointed out by 

 Blondlot, there will be a loss of arsenic. It will be found better for 

 the conversion of the arsenious into arsenic acid, to use strong nitric 

 instead of nitro -muriatic acid, (as recommended by Orfila,) as this 

 will avoid the volatilization of arsenic as chloride. After heating the 

 mixture to expel all nitric acid, the ash may be drenched with water 

 until all that is soluble is removed. This may be brought to drvness 

 in a porcelain vessel, and again treated with nitric acid several times. 



