26 Br. Christtiodt Reply to Mr. Phillips. [luLt, 



when the solution is considerably diluted. A solution, contain- 

 ing, like yours, a grain per ounce is stronger than will generally 

 occur in the practice of medical jurisprudence. What would be 

 the result with your process if, as in two cases which were lately 

 submitted to me, and in which, as you will see by my paper in 

 the Edinburgh Medico-Chirurgical Transactions, I detected the 

 poison by my method, the proportion was twenty-five, or a hun- 

 dred and seventy times less ? Would not an attempt to destroy 

 the colour inevitably remove the whole arsenic I 



Another criticism you make on my objections to your process 

 19, that I probably did not wash my ivory-black. Most assur- 

 edly I did not. First, because I ascertained that the muriate or 

 muriates contained in my ivory-black were far too scanty to 

 affect the colour of the silver precipitate even in a pure solution; 

 and secondly, because, as you should know very well, the fluids 

 I examined gave a copious white or coloured precipitate with 

 the silver test, independently of the impurities m the charcoal. 

 At your request, however, I have repeated the experiments with 

 washed charcoal ; and I find the washing does not make any 

 material difference. 



Before concluding, I must take the liberty of saying, that in 

 common with other distinguished writers on this subject, you 

 have fallen into the error of treating it too much as a chemist, 

 and too little as a medical jurist. You must be aware that 

 evidence which will satisfy the former will not satisfy the latter; 

 — that the indications of one or two liquid tests would be satis- 

 factory in a common chemical analysis; but that far greater 

 precision is required when the analysis will decide a question of 

 life and death. The analyzer must be able not only to satisfy 

 his own mind, but likewise to satisfy the Court that his conclu- 

 sions are legitimately drawn. My attention was first turned to 

 the subject, because the complexity of the ordinary processes 

 rendered the latter object unattainable ; and my first view was 

 rather to render the process simpler, than to make it delicate, 

 because I perceived from what took place on several trials that 

 judges and jurymen were inclined to distrust the chemical 

 evidence altogether, seeing that it was surrounded by so many 

 fallacies, and was too complex to be comprehended by their 

 uninitiated understandings. My aim, therefore, was to substi- 

 tute a process which might be so simple as to be easily applied 

 by unpractised operators, and easily explained to unscientific 

 persons in a court of law. Whether 1 have succeeded it becomes 

 not me to judge. The method I propose [in which of course 

 there is nothing new but the combinations and precautions] has 

 at all events many advantages over your decolorizing process, 

 and every other process now in use. 1. It is much simpler. 

 2. It is applicable to every possible case. 3. It is more dehcate 

 than some, and, kioking^ to th$ object in view, the procuring 



