120 Reply to a Review in Bra?ide's Journal of Science ^ 



To which assertions I beg to apply the following answers : 

 Answer 1. The chemical history of prussic acid is not adverted 

 to superficially in my treatise. It is more fully given, than 

 in many recent works on chemistry. It is a hundred times 

 more extended than that substituted by the reviewer for 

 the edification of his readers. 

 Proofs. Mv chemical history of Prussic Acid begins from the 

 discovery of Prussian blue, and terminates with the latest 

 researches respecting the component parts and real na- 

 ture of the acid itself, by Gay-Lussac, whose notions and 

 atomic theories are fully given ; while the intermediate 

 epochs of this interesting history are duly noticed, the 

 labours of several eminent chemists, particularly those 

 of Morveau, Scheele, Bertholiet, &:c. as well as those of 

 M. Porrett, in this country, are mentioned; and con- 

 tinued reference made throughout the section, as well as 

 at the conclusion of it, to various works in which the 

 subject has been treated in the most satisfactory manner. 

 The historical account above alluded to occupies tiueniy- 

 four printed pages of my work ; while not one-third 

 of that space, in the most approved modern works on 

 chemistry, has been dedicated to that subject, excepting 

 in the laborious and classical system of chemistry by 

 Dr. Thomson. The chemical history of the same sub- 

 stance, substituted by the reviewer himself, occupies just 

 twenty-nine lines. 

 CoROLLARV. O's assertion, therefore, respecting my *' super- 

 ficiality," is incorrect. 

 Answer 2. It is not true, that I have given the different pro- 

 cesses for preparing the acid *' without any sufficient re- 

 marks upon their principles." 

 Proofs. My description of Scheele's process, written witli 

 what perspicuity I could master, is followed up by a com- 

 plete rationale oi the various steps of that process, which 

 had been ambiguously interpreted by others ! Of Vau- 

 quelin's process I observed that its simplicity would ren- 

 der any remark of mine upon it an act of supererogation 

 — and on the third, or Majendie's process, consisting in 

 the mere dilution of the concentrated acid with water, I 

 made sufficient remarks to attract the notice of the re- 

 viewer, who has grounded upon them a whole and long 

 paragraph concerning their pretended incorrectness ! 

 Corollary. O's assertion, therefore, is again, in this instance, 



" unjust." 

 Ansrier 3. The judgement I passed on the different processes, 

 is so far from being *' not tempered with mercy," that in 



two 



