122 Rf^phj to a Review in Brande's Journal of Science. 



quiry in question in the sliglitest degree : so that the 

 " epitome of what is known," may be well compre- 

 hended in the two pages that I have dedicated to that 

 subject. 

 Corollary. The reviewer, therefore, is on the present oc- 

 casion, as on all the preceding ones, wanting in "justice " 

 as well as " candour." 

 But I have done more : — I have given an extract from my 

 notes, taken while attending a course of lectures on animal che- 

 mistry, delivered by Vauquelin, in which an endeavour is made to 

 place the above subject in a somewhat clearer light. Yet what 

 is the conduct of O on this occasion ? With the same vonchn- 

 Innce with which he had, just before, talked of the urdnteUigili- 

 lily of two paragraphs borrowed from Bertholiet and Thenard, 

 he assures his readers, that the extract from Vauquelin's lectures 

 is not a tittle more intelligible ; and dismisses it without any 

 quotation in support of his affirmation. Now, as I mean, through- 

 out this letter, to substantiate by proofs what I advance on the 

 score of O's candour and justice ; and as I hesitate not to assert, 

 that the charge of unintelligibilitv against Vauquelin is as gross a 

 defection from truth, as that which characterizes the charge brought 

 against his process for preparing the hydrocyanic acid, I shall 

 beg leave to (|Uote, once u:iore, the passage in question, in order 

 tliat the reader may judge, whether or not it be uninteUigille, 

 " When animal substances are exposed to heat with a mixture 

 of alcalies — hydrogene, carburetted, and carbonic gas are ob- 

 tained, besides a residuum, which, if washed in water, will be 

 found to contain prussic acid. The alcali, therefore, seems ne- 

 cessary to form the prussic acid, by attracting together the prin- 

 ciples of which it is constituted," &c.* If this be unintelligible, 

 then plain language is not capable of expressing common ideas; 

 but if, on the contrary, the passage be found perfectly compre- 

 hensible, and such, indeed, as will be met in substance, in the 

 works of most men of eminence who have written on the same 

 subject, then the conclusion regarding the reviewer's candour is 

 unavoidable. 



The reviewer's charge, at page 406, of my having unnecessa- 

 rily separated the account of the physical properties of the prussic 



* It is not a little curious, that one of the most important works on Che- 

 mical Scicnco, written in the English lnn2;'iiif!C, should contain a passage 

 nearly similar in import to the above, on the sul'ject of Prussic Acid. Hav- 

 jns; described the process of hcatint; blood and alcalies, to procure the acid 

 — the author proceeds to j;ive the following explanation of tliat process: 

 "This process consists essentially of two operations, one the impregnation 

 of the alcali with that peculiar principle contained in the blood, which gives 

 the power of strikini; a bine colour with iron, and is called the prussid acid," 

 (S:c. Vide Aikiu's Dictionary of Chemistry, .-lirt. Prussian Blue. 



acid, 



