Notice of a Manual of Chemistry. 333 
the third describes the various methods of estimating the specific 
gravities of solids, liquids, and gases. The author in this chap- 
ter has not confined himself exclusively to an account of matters 
as they are at the present time, but to a certain extent has com- 
bined historical with practical information ; thus furnishing the 
student with sufficient knowledge of the views and opinions en- 
tertained at various periods, to enable him easily to trace the pro- 
gress of the science through various devious paths to its present 
State of advancement. 
The third chapter is occupied with “ Inorganic Chemistry,” and 
contains a history, an account of the nature and properties, aud 
the methods for the obtaining, of oxygen, hydrogen, nitrogen, 
carbon, sulphur, chlorine, &e. &c., and also a description of their 
compounds. The various theories of combustion are herein spo- 
ken of, the analysis and synthesis of water shewn, eudiometry is 
described, and numerous other important topics are discussed. 
Under the section on carbon, whilst speaking of carbonic acid, 
the important results of the experiments of Dr. Mitchell of Phila- 
delphia, on the liquefaction and solidification of this gas, are sta- 
ted. On Plate I, facing page 13, will be found represented the 
apparatus of Mr. Adams, which was contrived for the purpose of 
obtaining the gas in asolid state and on a large scale. It is accom- 
panied by a full description of every part of the generator and re- 
ceiver, of the proportions of the materials used, of the method of 
charging the generator, and of the manner of obtaining the solid 
result. It is the only account of this apparatus which we have 
seen ; and it seems hardly credible that. it can sustain uninjured, 
the immense pressure to which it is subjected. It has however 
been fully tested, and we presume is the same with which Dr. 
Webster obtained the very large quantities of this solidified gas, 
which we understand he exhibited in his lectures before several 
Societies during the winter just past. 
The fourth chapter includes, under seven sections, an account 
of the metals. All of the important characters and properties of 
each are given, and then follow descriptions of the oxides, chlo- 
rides, &c. 
In the fifth chapter we find the salts of the metals. These are 
arranged under four orders ; the author very wisely adopting the 
division into oxy-salts, hydro-salts, sulphur-salts, and haloid-salts, 
Which we deem the best that has yet been devised. The com- 
