360 Analysis of Scientific Books and Memoirs. 



twice this quantity of nitrate of red oxide, that is 40. .5 ; in doing which, 

 it is evident, that nitrous gas would be evolved equivalent to two of oxy- 

 gen as Mr Dalton found ; and the remaining 25 of mercury may have 

 divided into two parts, forming with two atoms of nitric acid (13.5) /fV^/, 

 nitrate of red oxide (12.5 metal + 1 oxygen + 6.75 acid = 20.25) and 

 second, hyponitrite of red oxide (12.5 metal + 1 oxygen + 4.75 acid = 

 18.25,) and this 18.25 of hyponitrite would evidently decompose oxymu- 

 riate of lime equivalent to two of oxygen, as Mr Dalton also found. One-» 

 fourth of the mercury would thus produce hyponitrite of red oxide, and 

 three-fourths nitrate of red oxide. This is a result which may have eluded 

 any other mode of investigation than that employed by Mr Dalton ; for we 

 learn from his paper alluded to, that the hyponitrite of mercury readily ab- 

 sorbs oxygen from the air, becoming a nitrate. 



Red oxide of lead seems to us a compound, the nature of which requires 

 further investigation. Doctors Berzelius and Thomson agree in the state- 

 ment, that after being treated with vinegar, 27 parts dissolved in nitric 

 acid leave nearly 14 of brown oxide. But before being treated with vine- 

 gar, Mr Dalton (p. 46) says that nitric acid leaves only one part of brown 

 oxide out of five of red lead. M. Longchamp found only one left out of 

 six ; and M. Houton-Labillardiere found one left out of four of a crystal- 

 lized specimen, {Ann. de Chim. et Phys. vol. xxxiv and xxxvi.) Even al- 

 lowing for the accidental presence of litharge (though 50 or 60 in the 

 100 appear excessive) there is reason to suspect that an oxide of lead may 

 exist consisting of three atoms of metal and four atoms of oxygen. 



The red oxide of iron is considered by IMr Dalton as a compound of one 

 atom of oxygen with two atoms of black oxide of iron. In the present 

 state of chemistry this view is probably the simplest and the most plausible 

 that has been proposed. Other statements respecting the oxides occur not 

 devoid of interest ; but having dwelt thus long on this part of the work, 

 we must beg to refer our chemical readers to the volume itself. The next 

 section treats of the sulphurets. We do not dwell upon this subject, be- 

 cause the interest of Mr Dalton's statements is now susperseded by the sub- 

 sequent discoveries of Berzelius and Berthier. 



The next section treats of phosphurets. The most interesting part of 

 this section consists of some corrected statements respecting phosphuretted 

 hydrogen. This is the most unfortunate of all compounds. It has been 

 successively investigated by Davy, Dalton, Thomson, Dumas, and Rose ; 

 and all disagree. Much as has been done, new experiments are still re- 

 quired. Probably the paper of Dumas would be the best starting point. 

 That of Rose proceeds too much on deduction, and includes too many as- 

 sumptions to inspire us with confidence. 



Under the section of the carburets, Mr Dalton's opinion of the nature 

 of steel merits grave consideration. 



" From the above account of steel, it is evident there is an essential differ- 

 ence between it and pure iron. That difference consists, according to the 

 common opinion, in steel being a carburet of iron, or carbon and iron 

 united. The fact of the union of carbon and iron in the formation of steel 

 does not seem to me satisfactorily proved^ Mr Collier asserts that iron 



