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 VIII. Notices 7-especting New Books. 



The First Lines of Philosophical and Practical Chemistry, Ssc By 

 J. S. FoKSYTH, Surgeon, &c. 



AN opinion is generally prevalent among writers, that it is advan- 

 tageous to them to possess some knowledge of the subject which 

 they undertake to explain and illustrate j but unless the principles and 

 practice of the maker of the book now under consideration are in di- 

 rect opposition to each other, he entertains views on this subject 

 totally different from those of most authors. Mr. Forsyth's great ta- 

 lent lies in copying; and though in the exercise of it, truth and error 

 are in general equally welcome to him, yet in some instances, by a 

 happy stretch of his powers, he contrives to expunge fact, and replace 

 it by fancy. We shall not fatigue either ourselves or the reader with 

 discussing the merits of Mr. P^orsyth'm arrangement : it is universally 

 agreed to be a matter of secondary importance ; never by its defects 

 converting that which is in other respects a good book into a bad 

 one, or by its lucidness rendering a middling performance excellent. 

 We have already hinted at our author's ignorance of chemistry; 

 and that the charge may be closely followed by proof, we shall im- 

 mediately proceed to offer it : a few instances taken at random will 

 be sufficient for this purpose. In page 281 it is stated that " Blue 

 verditer, much used for staining paper for hanging rooms, is a nitrate 

 of copper combined with hydriate of lime." Now blue verditer con- 

 tains neither nitric acid nor lime ; and although by hydriate of lime, 

 we presume our author's meaning (if he have any at all) to be hydrate, 

 — this amendment of the spelling will be none of his chemistry ; for 

 any one in the least acquainted with the subject, knows that nitrate 

 of copper is decomposed by hydrate of lime, and consequently that 

 no compound of tiiem can exist. It is, however, difficult to decide 

 whether Mr. F's memory or judgement is most defective; for he had 

 totally forgotten that at page 126 he had made the following state- 

 ment : " the blue pigment called verditer, said to be prepared by de- 

 composing the nitrate of copper by chalk, is an impure carbonate." 

 Again, in page 281, " The beautiful grass green colour of the shops, 

 called mineral green, is precipitated in a peculiar way from sulphate 

 of copper by means of caustic potash and oxide of arsenic. The co- 

 lour known by the name of Scheele's green, is an arsenite of copper.'' 

 .^Now it is evident, that the compiler of " The First Lines" is totally 

 ignorant of the facts, that oxide of arsenic is another name for arse- 

 nious acid, and that mineral green and Scheele's green are similar com- 

 pounds with different appellations. The oxalic acid (page 89) "cry- 

 stallizes in slender flattened quadrilateral prisms, terminated by two- 

 sided prisms." We have heard of prisms being terminated by pyramids; 

 but to find prisms terminated by prisms, is something new in the 

 science of crystallography ; and we should be curious to see a model 

 of a two-sided prism. With respect to clilorine, it is stated (page 96) 

 that " it possesses no acid properties — it has not a sour taste — does 

 not redden the blue colour of plants, and shows little disposition to 



unite 



