pe Ree 
of water. Now, as many acids are both formed 
and decomposed in the processes which are con- 
stantly going on upon a farm—as some by form- 
ing themselves may be drinking up the simple 
gases, while some by resolving themselves into 
their elements may be giving off these gases, it 
becomes useful to know which acids are formed 
by oxygen, which by hydrogen, which by chlorine 
or fluorine, which by oxygen with a metal, which 
oxygen with some other substance than a 
metal, and which by an union of chemical and 
vital action in the intricate organisms of vege- 
tables and animals. Most of the inorganic acids 
will be sufficiently understood for all the pur- 
poses of a farmer, if known simply as belonging 
to their respective classes, or as formed principally 
of oxygen and a metallic base, of oxygen and a 
non-metallic base, of hydrogen and either an 
earthy or a metallic base, or of elements different 
from those of the oxygen.and the hydrogen acids. 
Yet several of them act so prominent and exceed- 
ingly important parts either in the economy of 
vegetable life and growth, or in manurial opera- 
tion upon the soil, or in the processes by which 
| manurial composts are prepared, that they re- 
quire to be well-known in their individual char- 
acters and powers. Carbonic acid, in particular, 
demands thorough individual notice for its agency 
in supplying all plants with carbon, one of the 
very chief constituents of their bulk ; nitric acid, 
| for its agency in supplying the cereal grasses and 
other nutritious plants with nitrogen or azote, a 
distinguishing element in the composition of their 
alimentary pulps and juices ; phosphoric acid, for 
its agency in providing nutritious plants with 
phosphates, an invariable constituent of the seeds 
of all kinds of grasses, beans, pease, and lentils; 
and sulphuric acid, both for its immediate power 
as a manure on some special soils, and for its ex- 
tensive agency in supplying manurial salts, and 
in controlling important processes in the prepara- 
tion or enrichment of farm-yard manures. The 
organic acids, as a class, are far more compound 
in their constituents, elaborate in their forma- 
tion, and numerous in their chemical aspects 
than the inorganic acids; and as most of them 
are identified with only a class or a genus, or even 
a single species of organic substances, they can 
be properly understood only when individually 
studied and known. But so large a proportion 
are either obscure or of very limited existence, 
or of ill-developed character, or of feeble and un- 
important agency, that even a very intelligent 
farmer may discard them from his vocabulary 
without risk to either his interests or his reputa- 
tion. Hence only about four or five of the or- 
ganic acids, and so many of the organic as either 
exert an extensive agency, or possess a very dis- 
tinct character, are requisite topics for discussion 
in agricultural chemistry. 
We shall here name in a note the principal 
acids, as enumerated in the fourth edition of Dr. 
Ure’s Dictionary of Chemistry ; and we may state 
——————— _ a 
ACIDS. 
that many more have recently been discovered, 
and that a far fuller list of them, as well as an 
ample notice of each, may be obtained by con- 
sulting the works of Dr. Thomson, which we shall 
name at the close of this article.* All the or- 
ganic acids are decomposed by a red heat ; most 
of them yield at once carbon, oxygen, and hydro- 
gen ; and a few of them, in addition to these, 
yield nitrogen or azote. See articles Azortn, CarR- 
Bon, Hyprogren, and Oxyern. The vegetable 
acids, in a free or uncombined state, occur very 
often in fruit, occasionally in leaves, and more 
rarely in seeds and roots ; but, in a state of com- 
bination, they are usually met with in almost 
all parts of plants. The most important of the 
organic acids named below are the abietic, found 
in the fir ; the aceric, in the maple ; the acetic, 
in numerous vegetables; the amniotic, in the 
liquor amnit of the cow; the amylic in starch, 
or the farina of plants ; the benzoic, in the sweet- 
scented vernal grass, and sweet-scented soft grass, 
anthoxanthum odoratum and holcus odoratus ; 
the butyric, in butter; the caseic, in cheese ; the 
citric, in lemons, oranges, currants, and some 
other fruits ; the formic, in the liquor of ants ; 
the gallic, in most barks; the lactic, in milk or 
whey ; the lithic or uric, in urine ; the malic, in 
apples, and in the berries of the mountain-ash ; 
the oxalic, in sorrel; the pectic, in many vege- 
* The inorganic acids which contain neither oxygen 
nor hydrogen, are the chloriodic, the chlorocyanic, 
the fluoboric, and the fluosilic; the inorganic acids 
which contain hydrogen are the fluoric, the hydriodic, 
the hydrochloric or muriate, the ferrocyanic, the 
fluotitanic, the hydrobromic, the hydroselenic, the 
hydrocyanic, the hydrosulphurons, the hydrotellur- 
ous, and the sulphocyanic; the inorganic acids which 
contain oxygen with metallic bases are the arsenic, 
the arsenious, the antimonic, the antimonious, the 
chromic, the columbic, the manganesic, the mangan- 
esous, the molybdic, the molybdous, the selenic, the 
selenious, the titanic, and the tungstic ; the inorganic 
acids which contain oxygen with other bases than 
metals, are the boracic, the bromic, the carbonic, 
the chloric, the perchloric, the chlorocarbonic, the 
iodous, the nitrons, the nitric, the hyponitric, the 
hyponitrous, the iodic, the iodosulphuric, the hypo- 
phosphorous, the phosphorous, the phosphate, the 
phosphoric, the hyposulphurous, the sulphurous, the 
sulphuric, the hyposulphuric, and the cyanic; and 
the organic acids are the abietic, the aceric, the 
acetic, the aloetic, the amniotic, the amylic, the’ 
benzoic, the boletic, the bombic, the butyric, the 
camphoric, the capric, the carbazotic, the caseic, the 
cevadic, the cholesteric, the citric, the croconic, the 
delphinic, the ellagic, the formic, the fulminic, the 
fungic, the gallic, the glancic, the hircic, the hydrox- 
anthic, the indigoic, the igasuric, the kinic, the 
laccie, the lactic, the lampic, the lithic or uric, 
the malic, the meconic, the menispermic, the mar- 
garic, the melassic, the mellitic, the moroxylic, the 
mucie, the nanceic, the netro-lencic, the netro-sac- 
charic, the oleic, the oxalic, the pectic, the phocenie, 
the pinic, the purpuric, the pyrocetric, the pyrolithic, 
the pyromalic, the pyrotartaric, the rosacic, the sac- 
lactic, the sebacie, the silvic, the solanic, the sto- 
aric, the suberic, the succinic, the sulphonaphthalic, 
the sulphovinic, the tartaric, and the vegeto-sul- 
phuric. 
——— 
