36 Reviews, and Notices respecting New Books. 



nitric is known ; we have then "nitrous gas, popularly laughing gas." 

 Now nitrous gas means nitric oxide gas ; and if Prof. Rennie will 

 attempt to breathe it, he will probably term it in the next edition, 

 choking gas, if he should survive the experiment. We are further in- 

 structed, that this nitrous gas may be prepared " by exposing liquid 

 nitric oxide for some days to the action of iron filings." This is the 

 first time we have heard of the liquefaction of nitric oxide gas. Mr. 

 Faraday failed in the attempt to render it fluid. In p. 77 the " laugh- 

 ing gas" is again called nitrous gas. 



In page 78 we learn that arsenious acid " is sweet, a circumstance 

 which has occasioned cases of poisoning, by children mistaking it for 

 white sugar." Dr. Christison assures us that he and several of his 

 scientific friends (Prof. Rennie of course not present,) all agreed 

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

 very faint sweetish taste."* 



In p. 85 we have a new description of sulpho-salts. " The com- 

 pounds, to which Berzelius has given the name of sulpho-salts, have 

 a metallic base, combined with a double proportion of sulphuric 

 acid j " and in a note it is stated that compounds containing this 

 proportion of sulphuric acid are called "double sulphurets." Here 

 is " confusion worse confounded:" first, sulpho-salts do not con- 

 tain sulphuric acid at all j secondly, if they did contain a double 

 portion of it they would not be double sulphurets, but bisulphates. 

 Orpiment, we are informed, is a compound ** of sulphuric acid and 

 arsenic j " it contains no sulphuric acid j but if it "be dissolved in 

 solution of potass, the oxygen of a portion of the potass unites with 

 the arsenic, forming arsenious acid, " &c. Now if the arsenic were 

 combined with sulphuric acid, it must be already in the state of oxide 

 or arsenious acid, and consequently would not take oxygen from the 

 potash to become so. 



In page 145 we have a tissue of blunders : it is asserted that if in 

 a salt "the acid was in excess, the term super, hyper, or per was 

 placed before it, as persulphate of mercury. " The term per has no re- 

 lation to the quantity of acid in a salt, but indicates the quantity of 

 oxygen in its base ; persulphate of mercury means not supersulphate 

 of the protoxide of mercury, but sulphate of the peroxide. Once more ; 

 "when the acid was deficient, and the base in excess, the term sub 

 or hypo was placed before it, as sw&sulphate of potass." No such 

 salt as subsulphate of potash is known, nor (we believe) was ever sup- 

 posed to exist. Again ; the term hypo was never employed as de- 

 scribed, it designates the relative proportion of oxygen in the acid of 

 a salt, but has nothing to do with the quantity of the acid; hyposul- 

 phite of potash means a compound of hyposulphuric acid and potash, 

 not the Professor's imaginary subsulphate. More yet; " what was 

 formerly termed persulphate of potass, is now 6zsulphate of potass"; 

 persulphate of potass was never used to express bisulphate; it means 

 a sulphate of the peroxide of potassium, which cannot be formed, and 

 the term has therefore never been employed at all. 



These are a few of the blunders in this miserable abortion. 

 • See Phil. Mag. and Annals, N.S. vol. viii. p. 277. 



