Notices respecting Nnw Books. 179 



decomposition bv air. 6th. Dissolubility in water hot or 

 cold : decomposition more or less advanced by pure water, or 

 water aerated. 7th. Decomposition by alkalis and earths; 

 nature of precipitated metallic oxyds ; complete precipita- 

 tion, or formation of triple salts or trisules, partly alkaline 

 or earthy, and partly metallic. 8th. Alteration of metallic 

 oxyds at the moment of thefir precipitation, whether by air, 

 or by tiie nature of the alkali employed to precipitate them ; 

 as it happens with respect to ammoniac. Qth. Reciprocal 

 alteration by the various acids, decomposition or not; at- 

 traction of acids for metallic oxyds, ciiange of the oxyds 

 discoverable by their colour. 10th. Alteration by earthy or 

 alkaline salts presenting either an union without decompo- 

 sition, or a double decomposition. 1 1th. Reciprocal action 

 of mineral salts showing either a simple union, or a simple 

 change of bases by the acids, or a displacement of oxygen 

 which precipitates the two oxyds, the one because it is 

 partly disoxyded, the other because it is hvperoxyded ; such 

 is, for instance, the useful precipitation of the muriatic so- 

 lution of gold by the muriatic solution of tin, which yields 

 the purple precipitate of Cassius. I2lh. Union of iiulfurets 

 and hydrosulfurets, earthy or alkaline; formation of species 

 of sulphureous mines." 



The appearance of this improved edition of the " Philo- 

 sophy of Chemistry," as it has been very improperly called, 

 in its English dress, induces us to wish that, like the French 

 orator, the Englisli orator of science, Mr. Davy, to whom 

 this translation is dedicated, would devote some of his time 

 to give an improved edition of his " Syllabus of Lectures" 

 printed in 1802; we might then say that we have an ele- 

 mentary work on chemistry, worthy to rival the " Chemical 

 Philosophy" of M. Fourcroy, and which might also bv 

 translated into eicht living lanauages. The greatest defects, 

 indeed, of the present work, next to its on)ission of the 

 characters of the gases, and of eudiomctrical operations, are 

 a multiplicity of divisions without distinctions, and distinc- 

 tions without differences j a iuperabundancc of terms fre- 

 quently altogether uimccessary, and a gential redundiincy 

 of words, occasioned l)y an attempt at cxces'-ive ptr-picuiiy, 

 \i C which 



