162 
then received doctrines of Mohs, was rather a system than 
a science ; rather a system by which the place of a mineral 
in a classified list, grouped after little else than external 
appearances, could be determined by a few simple experi- 
ments, than a science dealing with the more subtle pro- 
perties and qualities of the objects it classifies, and treat- 
ing external resemblances as of no importance unless 
associated with analogies in composition or chemical 
type. No doubt it is to a great progress of mineralogy 
in this latter direction, associated as it has been with a 
corresponding development of crystallography and crys- 
tallographic optics, that the falling off in the votaries of 
these sciences is in a great measure due. 
The mere collector for collecting’s sake would prefer 
now-a-days to expend his money on shells or his research 
on fossils or plants, for a tolerable familiarity with which 
little preliminary education is needed, to investing his 
means and puzzling his mind with a science which has 
become a department of chemistry, and needs, besides 
sound chemical ideas, a thorough practical acquaintance 
with another and that a mathematical science, namely, 
crystallography. 
To a similar cause is due, in part at least, the compara- 
tive indifference with which crystallography is treated by 
chemists and mineralogy by our geologists. 
No doubt these two great sciences, chemistry and 
geology, between them coyer nearly all the ground occu- 
pied by mineralogy, But our chemists are engrossed by 
great problems that may be said to be involved in the 
nature, if not even in the structure, of the gaseous mole- 
cule; they have hardly yet turned to that side of the 
problem which will one day be illustrated by the physics 
of the crystal molecule. So again the geologist in his 
character of historian of the earth is occupied with the 
relations of the manifold forms of life that have congre- 
gated on our globe, and their distribution in time ; or else 
with the great dynamical causes that have engineered this 
“dzedal earth” of ours into its present superficial form. 
And in England the chemical causes to which so large 
an amount of change in the character and bulk of rocks 
and in minerals is due are rarely within the grasp of our 
leading geologists. 
In Germany it is otherwise. There, a preliminary edu- 
cation in mathematics or in chemistry, and by natural 
sequence in crystallography and mineralogy, is the almost 
universal introduction to the study of geology. So that 
to the German student, crystallography, as a science of 
observation with the goniometer, and of calculation with 
formule, is no rare accomplishment ; and the little collec- 
tion he makes during his student years, whether of minerals 
or of chemical preparations and crystals, forms a nucleus 
round which is gathered a great deal of valuable and 
exact knowledge, which he builds on work with his gonio- 
meter and his balance, and often with the microscope at 
home or his hammer in the field. The School of Mines 
here is producing a few men with many of these qualifi- 
cations, but it may be questioned whether a more mathe- 
matical basis is not needed in that as in other similar 
educational institutions in England. 
At any rate we do not turn out here the many-sided 
geologists that Germany produces, as witness the school 
of chemical geologists with Bischof at its head, or the 
admirable works on petrology by German authors; for 
NATURE 
[Dec. 9, 1869 
the German geologist does not write on rocks till he has 
acquired a scientific acquaintance with the minerals that 
compose them. 
In France, again, the nation of Haiiy, if mineralogy, 
perhaps from the smaller importance of French mining 
industry, is not so widely pursued as it is in Germany, it 
has nevertheless always had its careful, thorough, and 
scientific votaries. Indeed, in our own day, the researches 
of Des Cloizeaux, following up those of Grailich, and his 
brilliant little constellation of Viennese crystallographers, 
have shown how absolutely essential is the study of the 
optical constants of crystals to any complete science of 
chemistry or mineralogy. We may, indeed, console our- 
selves for our shortcomings in England by the reflection 
that to an Englishman is due a system of crystallographic 
notation, and an extended use in crystallography of 
spherical trigonometry, which have long given to that 
science a greater symmetry and simplicity in its formule; 
so that now the system of Professor W. H. Miller is 
gradually displacing every other on the Continent. 
But when we turn from Europe to America, we should 
expect that we should have to judge by other standards ; 
for there a sterner call summons men to the study of 
mineralogy than is the case in the Old World. Where any 
pioneer on a new bit of mountain land may light upon 
mineral wealth like that of the Washoo district of the 
territory of Idaho, there is a need for pioneers who are 
mineralogists ; and it is but justice to the American instinct 
for perceiving, and genius for supplying, whatever is wanted 
under novel conditions of life, to say, that in mineralogical 
science and mining enterprise the Americans have been 
equal to the demands and to the splendid opportunities 
that the New World has presented to them. 
Of this the work, the title-page of which heads this 
article, is an admirable evidence. Written to meet the 
wants of eager and intelligent young ore-seekers in the 
vast stretches of plain and mountain between the Atlantic 
and the Pacific, it has satisfied these wants perfectly, and 
helped to produce (we had almost written has produced) 
an admirable American school of mineralogists. But it 
has done more than this: it may almost be called the 
text-book of mineralogy for Europe ; and it is so for the 
reason that its ingenious and talented author is laborious ; 
and is not only laborious, but able to throw off a pre- 
judice like an old garment. It is this freshness of mind 
and power of work that has made the successive editions 
of his mineralogy not only wot reprints, but essentially 
original books, and even made them an interesting pyscho- 
logical study of one who may be taken as a typical Ame- 
rican man of science. 
The chief features that distinguish the large and hand- 
some volume representing Professor Dana’s new, that is 
to say, his fifth edition, are—Firstly, modifications in his 
system of classification; Secondly, alterations in the nomen- 
clature ; and Thirdly, a new chemical notation, Professor 
Dana still retains his peculiar graphic method for the 
representation of the zones of crystals and his notation for 
their planes. Both of these, we believe, he will discard in 
some future edition which we earnestly hope that he may 
live to carry through. The notation is rather complicated 
than simplified by the employment as symbols of the 
letter z in its different phases of italic and capital, which, 
together with the figure 1, are used to represent what, in 
