REVIEW OF MR. DANA’S CHEMISTRY OF SOIL. 
243 
REVIEW OF MR. DANA’S CHEMISTRY OF SOIL. 
In my last I promised to review Mr. Dana’s 
chemistry of soil, which I regret having under¬ 
taken, for the whole essay is such a jumble of 
mineralogical, chemical, and logical errors, as al¬ 
most to defy criticism. 
Page 22, Mr. D. says, “Elements are substances 
which have not as yet been proved to be compound. 
Minerals are called simple which have certain 
definite, external, physical characters, though they 
may be composed of several elements. Rocks are 
called compound, which consist of several simple 
minerals, as granite which consists of quartz, fel¬ 
spar, and mica.” 
So, according to the logical acumen of Mr. Dana, 
compound minerals are simple minerals. We 
must bear in mind that this is in a treatise on the 
chemistry of soil. 
Page 23, “ The mineralogist merely names his 
mineral, labels it,, and places it in his cabinet.” 
From several other observations of Mr. Dana’s, 
he intimates, that a mineralogist knows nothing 
of the chemical constituents of minerals. There 
is a wonderful aptitude in the human family, each 
one to consider himself as the standard of perfec¬ 
tion, and to measure everything by that standard ; 
yet St. Paul tells us this is not wise. As Mr. D. 
has displayed such total ignorance of the compo¬ 
nents of primitive rocks in his geology of soil, he 
must conclude, of course, that all mineralogists are 
equally ignorant. I have been personally ac¬ 
quainted with scores of mineralogists, and never 
found one, until Mr. Dana, who could not give a 
tolerably accurate description of the chemical con¬ 
stituents of any mineral in his cabinet. The 
names given to many minerals give no indication 
of their chemical components; but he must be a 
poor mineralogist who is ignorant of them. 
Mr. Brande says, “ Mineralogy is a branch of 
physico-chemical science, which teaches the prop¬ 
erties, composition, and relations of mineral bod¬ 
ies, and the art of distinguishing and describing 
them.” 
“ There is no branch of science,” says Sir J. Her- 
schel, “ which presents so many points of contact 
with other departments of physical research, and 
serves as the connecting link between so many dis¬ 
tant points of philosophical speculation, as miner¬ 
alogy. To the geologist, the chemist, the opti¬ 
cian, the crystal!ographer, it offers especially the 
very elements of their knowledge.” 
Pages 23 and 24, Mr. Dana goes on to say, “ The 
mineralogy of agriculture is no more than this, 
that the farmer be able ever to connect with a cer¬ 
tain name, a certain chemical composition.” 
“The amount of this mineralogical knowledge 
is very limited. Seven simple minerals compose 
all rocks, viz ; quartz, mica, felspar, hornblende, 
Sale, serpentine, carbonate of lime. Other min¬ 
erals are found in, but these seven compose all 
rocks termed, geological formations, and which 
form the crust of the globe.” 
“ The chemical constitution of rocks, the na¬ 
ture, properties, and relations of their elements, 
proves to be of the highest value, when it is known 
that the elements of these seven minerals are also 
the earthy parts of all plants.” 
It appears that Mr. D. has at last brought in 
carbonate of lime among rocks termed geological 
formations; although, at page 21, in his geology 
of soil, he merely gives 90 per cent, of silex, and 
only 85 of one per cent, of lime, and never men¬ 
tions lime as having any existence in geological 
formations. As he has grouped lime among the 
primitive rocks, I presume he refers only to what 
is termed primitive lime-stone, not knowing prob¬ 
ably that any of a newer formation had existence. 
Let us compare the minerals forming the crust 
of the globe as given at page 8 of Mr. Dana’s 
manual, with that at pages 23 and 24 in his chem¬ 
istry of soil. 
Page 8. 
1st series. Granite, 
Gneiss, 
Sienite, 
Greenstone, 
Porphyry, 
Basalt, 
Lava, 
Volcanic sand. 
These three 
Pages 23, 24. 
Quartz, 
Felspar, $ Granite. 
Hornblende, 
Talc, 
Serpentine, 
Carbonate of lime. 
2d series. Sand, 
Clay, 
Gravel, 
Puddingstone, 
Conglomerates, 
Sand-stones, 
Slates. 
I consider myself as a very indifferent mineral¬ 
ogist, yet I could not have committed the egregri- 
ous blunder of grouping mica and talc as two dis¬ 
tinct species of primitive rock, when it is well 
known, by the merest tyro in the science, that they 
are both of one species; talc being the sixth sub¬ 
species of rhomboidal-mica. See Professor Jame¬ 
son. 
Pages 24, 25, “ Of the fifty-five elements, four¬ 
teen are found in rocks. This includes the ele¬ 
ments of water, or oxygen, and hydrogen. Exclu¬ 
ding the last* and retaining oxygen in its various 
compounds, there remain twelve substances only 
in rocks. Of the earthy and metallic eight; and 
of the volatile and combustible, four only are found 
in soil. These all are called by names so familiar, 
that their enumeration conveys at once an idea of 
their distinguishing properties. These twelve sub¬ 
stances are divided, for the convenience of the far¬ 
mer, into three classes. First, silicates—second, 
urets —third, salts. The term urets, is here only 
used provisionally, and it is by no means intended 
to burden science with a new name, an act to be 
deprecated, where an old one will as well answer. 
But there is no old term, which includes the sub¬ 
stances to which, in the present subject, reference 
must be frequently made. It is more convenient to 
one to use a new term defined, than to enumerate 
by name, several substances, whose action in agri¬ 
culture has a common character, whenever this 
action is mentioned. The word inflammable, or 
acidifiable combustible, the usual chemical desig¬ 
nation might be used. But the farmer wants some 
more expressive term, which while it conveys all 
that is intended by the common word, shall also 
remind him of the peculiar character of those com¬ 
pounds with metals, and with each other which 
