SOi Notices respecting New Books, 



whether solids or fluids, in which no mechanical mixturcfs" 

 can be suspected, and where no partial decompositions can 

 have taken place. 



*' Thus, if sulphuric acid be poured into any solution of 

 baryta, the solid precipitate of sulphate of baryta which falls 

 down, is uniform in its nature, and always contains about 

 34 of acid, and 6f) of baryta ; and the case is the same 

 with other similar compounds, and with neutral salts in 

 general. 



" And if two neutral salts mutually decompose each other, 

 in the interchange of principles, there is never an excess of 

 acid or of basis *, and the resuhing compounds are likewise 

 perfectly neutral. Thus, if 100 parts of nitrate of baryta, 

 which contain 41 nitric acid, and 59 baryta, be mixed with 

 67 of sulphat of potash, which consist <if 30 of sulphuric 

 acid, and 37 potash, there will be found 89 of sulphat of 

 baryta, and 78 of nitrate of potash; so that 41 of nitric 

 acid will combine with the 37 of potash, and 30 of sul- 

 phuric acid with the 59 of baryta. 



" It is evident from these circumstances, that when one 

 body has the power of detaching another from its combi- 

 nations, it will always detach the j-ame proportion. Thus, 

 from whatever basis baryta attracts sulphuric acid, it will 

 always detach the same quantity ; and the same quantity 

 of potash, from whatever acid it precipitates magnesia, will 

 always throw down the same proportion. 



" 8. In cases when an alkaline substance combines with 

 more than one proportion of acid, the same circumstances 

 seem tooccurasin the combinations of gaseous bodies. The 

 proportion is either a multiple or adivisor of the first ; this is 

 shown by a very simple experiment, first made by Dr. Wol- 

 laston : let a given weight of the salt, called carbonate of 

 potash, be thrown into a tube over mercury, and diluted 

 sulphuric acid, sufficient to cover it, be introduced into the 

 tube, a certain volume of carbonic acid gas will be disen- 

 gaged ; let an equal weight of the salt be heated to redness, 

 when it becomes a subcarbonate, and let this subcarbonate 

 be treated in the same way, it will be found to give off ex- 

 actly half as much carbonic acid gas. 



" 9. In the combination of solid and fluid substances 

 which have not yet been decompounded, with gases, and in 

 the union of compound inflammable bodies with each other, 



* MM. Gay Lussac and Thenard have lately stated, '• that in some mu- 

 tual decompositions of fluates and muriates, slightly acid solutions become 

 alkaline, /^c/ieicfees, torn. ii. page 2S. But such changes must be complicated; 

 and perhaps a minute investigation may show that they are not anomalous. 



and 



