Intelligence and Miscellaneous Articles, 605 



cautions against too hasty inferences from the algebraical results, 

 (the great scientific vice to which the method itself is calculated to 

 give birth,) the reiterated suggestions respecting the kind of caution 

 to be observed in interpretation, and the repeated explications of the 

 singular and seemingly absurd expressions that result from the investi- 

 gation, — these, more than in any work we are acquainted with, render 

 it a valuable book of early study. The unity of the system of develop- 

 ment too, — the logical concatenation of the several parts, — the gene- 

 rality and completeness of the methods ; — these give it a character pe- 

 culiar to itself amongst English works on the subject, and a peculiarity 

 which every judicious teacher knows how to estimate properly. 



We remark, too, much that may be called original in method ; 

 more, indeed, than in an elementary book we should reasonably look 

 for. To one point only can we advert here. 



The doctrine of curvature has always been the great obstacle to 

 the production of a treatise on the conic sections, which should not 

 either directly or implicitly involve the employment of the principles 

 of the differential calculus. This difficulty is at length overcome 

 by Professor Young, and the entire investigation is rendered one of 

 purely elementary algebra. It would have given us pleasure to be 

 able to transfer it to our pages ; but as the work is accessible to our 

 readers, we think it unnecessary to do so. 



LXXXVI. Intelligence afid Miscellaneous Articles, 



TARTARIC AND PARATARTARIC ACIDS, ETC. 



M DUMAS has read before the Royal Academy of Sciences of 

 • Paris, a report in his own name and those of MM. Robiquet 

 and Pelouze, on a memoir of M. Fremy, relating to the modifications 

 which heat occasions in tartaric and paratartaric acids. 



It was first remarked by M. Braconnot, that tartaric acid when 

 submitted to fusion was changed in its properties. M. Fremy has 

 investigated this subject, and stated the results in the memoir now 

 reported. The reporter observes, that the nature of the oxygenated 

 acids may be explained by two theories, both of which are probably 

 true, but which are probably only applicable to a certain number of 

 bodies. One of these theories, and that which is almost universally 

 admitted, consists in regarding them as distinct bodies, as true 

 oxygenated acids, which combine with water and bases to form salts. 

 The other theory does not regard these as acids when they are an- 

 hydrous, but considers them as hydro-acids, and their salts as ana- 

 logous to the chlorides. 



These two theories are most opposed to each other in relation to 

 the nature of tartaric acid ; for one of them, that which considers tar- 

 taric acid as an oxacid, is incompatible with the analysis of anhydrous 

 emetic tartar ; and if, according to the composition of this sub- 

 stance, tartaric acid is considered as an hydracid, a difficulty im- 

 mediately occurs in accounting for the results obtained by M. Fr^my ; 

 these are indeed much more easy of explanation in considering tar- 

 taric acid as an oxacid, as will appear on examination. 



