
\ 

1891.] © Recent Literature. 995 
RECENT LITERATURE. 
Doelter’s Allgemeine Chemische Mineralogie’ is a collec- 
tion in logical order of all those facts relating to the chemistry of 
minerals that are so interesting to the modern mineralogist. After 
discussing crystal structure in its relation to the chemical molecule, 
and defining isomorphism, isomerism, polymorphism, and isoganism, 
and briefly touching upon morphotropism, the authof describes the 
ordinary methods of chemical analysis, and then occupies about seventy 
pages in a treatment of the subject of mineral synthesis. It is this 
latter portion of the volume that is most interesting. The author is 
himself such an indefatigable worker in this line of investigation that 
his remarks on the manufacture of minerals must be accepted as worthy 
of great confidence. Everywhere in these pages he writes himself 
master in his chosen study. He distinguishes clearly between terms 
that seem to approach each other in meaning, and defines them in 
such simple language that they need no longer be misunderstood, 
He divides the subject into two parts,—viz., the recrystallization of 
mineral substances already prepared, and the production of minerals 
and their crystallization. Under each head the methods that have 
proven most satisfactory for the purposes desired are given in detail, 
and following these is a bricf but sufficiently full account of experi- 
ments that have yielded mineral products, with references to the arti- 
cles in which they are described. Nearly every synthesis that has 
ever been made may be traced by the aid of the book,—a feat that 
has heretofore been possible only with the greatest difficulty. The 
last three parts of the volume deal with the chemical changes effected 
in minerals by change in temperature and by the action of solvents, 
the formation of minerals in nature, and the chemical composition and 
constitution of minerals. 
Though the book is not as complete as is Lehmann’s Molecular 
Physik in its treatment of those subjects that both discuss in com- 
mon, it serves as a supplement to Lehmann’s wondertul production, 
and demands a place beside this in every mineralogist’s library. — 

Fewkes’s Ccelenterates and Echinoderms.’—Dr. Fewkes has 
presented the New England student of the old group of Radiates a 
; a nM pp. 278, illus. 14. 
; the Collector of the Coelenterata and Echi nodermata of New a By 
cee Walter Foske — —— Institute, Vol. XXIL., Pp. 9: Salem, 


