Dr. Christison's Treatise on Poisons. 277 



Dr. Christison has divided his work into two principal parts ; the 

 first of which treats of poisoning in general, and the second of 

 individual poisons. His object in the former, is to consider the 

 physiological action of poisons, and to lay down those principles 

 relative to the management of cases of poisoning, which apply ge- 

 nerally to the subject. The individual poisons are considered under 

 the three classes of Irritants, Narcotics, and Narcotico-acrids. The 

 first divison comprehends those poisons, the principal action of 

 which is to excite inflammation in the parts where they are applied ; 

 the second, such as act solely or chiefly by producing disorder 

 in the nervous system ; and the class of narcotico-acrids includes 

 those which possess a double action, the one local and irritating, 

 and the other remote, consisting of an impression on the nervous 

 system. The subjects discussed in the first part are too exclusively 

 medical for our pages : we shall extract from the history of the 

 individual poisons such portions as will serve both as specimens of 

 the work, and convey useful, and in general new information to the 

 reader. 



Arsenic. — As very incorrect notions prevail respecting the taste 

 of arsenious acid, we extract Dr. Christison's remarks on this sub- 

 ject. " It has long been almost universally believed to be acrid, 

 and is described to be so in most systematic works, and in many 

 express treatises: but in reality it has little or no taste at all. The 

 reader will find some details on this point in a paper I published 

 lately in the Edinburgh Medical and Surgical Journal. In the 

 present work it is sufficient to observe, that 1 have repeatedly made 

 the trial, and seen it made by my request by several of my scien- 

 tific friends ; and that after continuing the experiment as long and 

 extending the poison as far back as we thought safe, we all agreed 

 that it had hardly any taste at all, — perhaps towards the close a 

 very faint sweetish taste. I have hitherto found only one authority 

 who has made the observation that arsenic has no taste, — namely, 

 Dr. Addington, the chief Crown witness on the trial of Miss Blandy ; 

 a few others, and more particularly Hahnemann, Dr. Gordon, and 

 Mr. Walker, a witness on a late trial, have said that it is sweet ; but 

 all the other authors I have consulted mention that it is acrid, and 

 one of these, Professor Fodere, even says that a grain causes an 

 indescribable and insupportable metallic taste. It is impossible to 

 make with safety satisfactory experiments on its taste, when it 

 reaches the back of the palate ; but we may rest assured that it 

 often makes no impression at all, as it has been swallowed unknow- 

 ingly with articles of food. This fact it is essential to remember, 

 as many ignorantly believe that when swallowed, even in moderate 

 quantity, it must cause a sense of acridity. I have not been able 

 to find any actual case where this sensation was perceived ; and it 

 is therefore probable that the mistake, which the present remarks 

 are intended to rectify, has arisen from the impression in the act of 

 swallowing having been confounded with the inflammation in the 

 throat subsequently developed along with the other inflammatory 

 symptoms. And so Navier remarked, that the solution has at first 



a bland 



