Botany and Zoology. 403 
aper commencing at page 106 of the same volume, Ram- 
iikes, treats of the composition of Stlicates. 
18, An Elem gine Treatise on Quartz a nd Opal, ipomiing their 
ties in which they occur ; 2 by, aces WituiaM Tram. ‘N ew edi- 
tion, greatly enlarged. 74 pp. 12mo. Edinburgh, 1870.—This 
beautifully printed little mineralogical volume contains descrip- 
tions of the many varieties of quartz and opal, with observations 
c 
Ill. BOTANY AND ZOOLOGY. 
1. How Crops Feed; a Treatise on the Atmosphere and the Soil 
as ee to the nutrition of Agricultural Plants, with pes 
ons; by | SamMusEL W. SORE, M.A., Prof. Analytical and y 
phy, &e, core at 
Sra whom “ numerous additions have been 2 ed 
tion are orale h seems unj 
the present sala. in considering “how crops feed,” Prof. 
Johnson is in fullest force, upon ground that he has complete mas- 
tery of; and consequently he has produced a compendium of what 
is known of the ¢ hemistry and physics of vegetation which is emi- 
nentl ger and satisfactory, and which supplies a long felt want. 
The first division of the book is devoted to the atmosphere, the 
Second to the soil as aa to vegetation ; Pe the action of the 
various elements of each upon plants, especially the staple plants 
of agriculture, — of ee ger upon them, i is in turn consi side: yagi with 
unusual a gis th 
dow of ae 
we and therefore roduce or nemnpere carbonic acid, and, on 
more de fini bet is great operation which produces the 
‘materials a get ag and eet: itself, which is the conversion of 
