846 
THE GARDENERS’ CHRONICLE. 
| DECR2; 
Indian corn in sulphydrate of ammonia. The relative 
proportions of oil in the different varieties of corn was 
shown by sections of the kernel, also the relative propor- 
tions of the zeine of Gorham or the gluten of corn. The 
causes of the peculiar explosion and evolution of the 
starch and gluten of corn in parching was explained by 
the decomposition of the oil in the cells of the transparent 
portions of the grain. Dr. Jackson had observed, in 
April, 1840, while analysing the ashes of Indian corn, that 
after combustion of the corn in a platina capsule, at a 
high temperature, the platina was rendered brittle, and 
was in part converted into the phosphuret of that metal. 
On examining into the cause of this, he discovered phos- 
phoric acid united to some volatile or destructible base, 
mixed with the phosphates of lime and of magnesia. His 
subsequent researches satisfied him that the volatile base 
in question was ammonia, which he separated by the 
action of potash and lime, at a temperature below that 
required for charring the grain. By the action of nitric acid 
he burnt out the carbonaceous matter from the ashes of 
corn, and procured a considerable quantity of glacial phos- 
phoric acid. In all these experiments, thus far, the whole 
grain was employed. In May, 1842, Mr. A. A. Hayes, 
of Roxbury, exhibited to the chemical association some 
specimens of southern corn, which had been cut in two 
and soaked in a solution of sulphate of copper ; and this 
test most beautifully marked out the limits of the phos- 
phates in that grain. Profiting by this interesting experi- 
ment, and observing that the phosphates were indicated 
only in the cotyledon of corn, Dr. Jackson dissected out 
the cotyledons, analysed them separately; and glacial 
phosphoric acid, phosphate of lime, phosphate of mag- 
nesia, and ammonia were obtained. The i in 
manner in which Professor Liebig was so ill-advised as to 
attack Vegetable Physiologists, of whose science he knows 
much less than they of Chemistry. The issue of all this 
has been productive of much good. Had it not been for 
English trumpets, public attention would never have been 
so strongly directed to Professor Liebig’s excellencies ; 
and we have to thank the German catcalls that his own 
thoughts have been so advantageously turned to the 
correction of his deficiencies. The two together have pro- 
duced a book infinitely superior to its predecessors, and 
to a very considerable extent unlike them. We hear no 
more of Starch consisting of concentric layers of wax and 
amylin; the exaggerations about grand experiments on 
woods and meadows are omitted, as is the materialism 
about the unimportance of a vital principle (p. 56, Ed. 2), 
and the offensive observations upon Physiologists. In the 
place of these and other subjects that are cancelled we have 
a very considerable quantity of new matter. A new 
chapter is devoted to the consideration of ‘‘ the Formation 
of Arable Land,” another to ‘ Fallows ;’’ that on the 
“Rotation of Crops ’’ is almost entirely rewritten, and so 
is the chapter on Manures; while a thirteenth chapter is 
devoted specially to a general retrospect of the theories 
included in the previous pages. To these are added 
supplementary chapters on the sources of ammonia, and 
on the questiorts whether Nitric acid is food for plants, 
and whether the nitrogen of the air takes a part in vege- 
tation. In an Appendix are given at length the important 
experiments of Wiegmann and Polstorf on the food of 
plants. 
In the former editions ammonia was the great subject 
of discussion. As chemists seem agreed in considering 
the ashes of the whole corn was but 1 per cent: of phos- 
phates of lime, magnesia, and free phosphoric acid, and a 
little silica. The cotyledons taken separately gave 6.4 
per cent. of fusible matter, which ran freely when melted. 
It consisted vf—Phos. lime, 2°4; phos. acid, 3:2; phos. 
magnesia, 0°8. He also made an extensive series of 
researches on other seeds, both of the Monocotyledonous 
and Dicotyledonous plants, which determined the existence 
of the phosph lusively in their cotyledons. The spe- 
cimens to which Mr. Hayes’ test had been applied, and 
which were exhibited to the society, were Peas and Beans 
of various kinds, Squash and Pumpkin seeds, Horse- 
Chesnuts, the common Chesnut, Pea-nut, Barley, Oats, 
Wheat, Rye, Buckwheat, and Cocoa-nut ; also Potato 
tubers and Turnip bulbs. In all these the existence of 
phosph was d trated. In Almonds, Walnuts, 
Butternuts, and most oily seeds, the sulphate of copper 
fails to demonstrate the presence of phosphates. The 
application of tincture of iodine proved the presence and 
limits of starch in the Turnip, and in several other plants 
which were exhibited. A sample of the hard and trans- 
parent portion of Indian corn, from which the oil and zeine 
had been removed by alcohol and ether, was proved by the 
iodine'test to be starch. It was observed that weak tincture 
of iodine does not colour this portion of the corn until the 
oilis removed. If strong tincture of iodine is employed, 
the alcohol removing the oil causes the freed starch to 
take the blue colour. Beans and Peas, consisting mostly 
of legumine, discovered by Braconnot, do not take a blue 
colour like the starch containing grains, but become dark 
brown. Specimens of various germinated and growing 
plants were also tested before the society. In the Potato- 
sprout the starch was traced up into the plumule about 
half an inch, where it disappeared, and dextrine was 
present, the starch having undergone a metamorphosis 
into that substance. Similar experiments were tried on 
Indian corn, which had been grown about two inches 
high, in pure powdered quartz. The changes which the 
seed had undergone were quite interesting, and it was 
seen, by the iodine test, that the starch of the albumen 
had been absorbed, and was changed in the plumule into 
dextrine and sugar. The portion of the corn, where the 
oil exists with starch and gluten, had begun to change, 
and iodine instantly forms a blue compound with the 
starch. On applying the sulphate of copper the presence 
of phosphoric acid in the radicle and plumule, and a little 
around it, was readily proved. On testing germinated 
English Beans the presence of phosphates was demon- 
strated in the cotyledons, but iodine did not prove the 
formation of starch fromthe legumin. ‘The same experi- 
ment was performed with the common Bean, with the 
same results. It will be interesting to study the changes 
which legumin (a substance now supposed to be identical 
with caseine), undergoes in the process of germination. 
As yet we know of no chemical researches on its trans- 
formations in the living plant. Dr. J. had observed that 
Cueurbitaceous plants contained nitrate of potash, and had 
consequently directed its application around the roots of 
such Vines. Observations on such plants grown on 
nitrous ground, where old barns had been removed, proved 
the value of that salt as a manure for Squashes, Pumpkins, 
and Melons.—Proceedings of Boston Society of Natural 
History. 
Reviews. 
Chemistry in its Applications to Agriculture and Phy- 
siology.’ By Justus Liebig, M.D. 8vo. Taylor and 
Walton. Tutrp Epitron. 
“Ir is rather more than three years since this remarkable 
book was laid before the British Association. In the 
course of that time two Editions have been printed ; 
they have been received on the one hand with most extra- 
vagant praise, and on the other with unmeasured censure. 
The first was attributable to the clearness with which some 
views that are really new, and others that are thought so, 
were brought before the public ; the second arose. from the 
it imp that plants should obtain their nitrogen 
directly from the air, and as all plants contain that 
element, ammonia seems to be the only source by which 
it can be supplied; and in all probability this is a just 
view of the case, Nevertheless it is by no means 
proved that larger quantities of ammonia than the atmo- 
sphere naturally contains are necessary to the most healthy 
vegetation ; and although it is certain that matter rich in 
ammoniacal salts is among. the most powerful of manures, 
it has by some been supposed that other substances con- 
stantly present along with the ammonia may be of 
equal or even greater importance. Such is sulphuretted 
hydrogen; such are phosphates. This opinion is now 
taken up by Professor Liebig, who devotes a whole chapter 
to its consideration. After stating that animal matter 
contains invariably the substances named albumen, fibrin, 
and casein, all three rich in sulphur, he inquires— 
“ From what source does the animal body derive these 
three fundamental components? Unquestionably they 
are obtained from the plants upon which the animals 
subsist; but in what form, and in what condition, are 
they contained in plants ? 
“ Recent investigations of chemists have enabled us to 
answer these questions with positive certainty. Plants 
contain, either deposited in their roots or seeds, or dis- 
solved in their juices, variable quantities of compounds 
containing sulphur. In these nitrogen is an invariable 
constituent. Two of the compounds containing sulphur 
exist in the seeds of cereal plants, and in those of legumi- 
nous vegetables, such as Peas, Lentils, and Beans. A third 
is always present in the juices of all plants; and itis found 
in the greatest abundance in the juices of those which we 
use for the purposes of the table. 1 
“«\ very exact inquiry into the properties and corhpo- 
sition of these substances has produced a very remarkable 
result, namely, that the sulphur-compound dissolved)An 
the juice of plants, is, in reality, identical with the anipu- 
MEN contained in the serum of blood, and in the whit of 
an egg ; that the sulphur-compound in the seeds of the 
cereals possesses the same properties and compositioip as 
the FrBRIN of blood: and that the nutritious constityent 
of Peas, Beans, and Lentils, is actually of the same nafure 
and composition as the casErn of milk. Hence it foljows 
that plants, and not animals, generate the constituents 
of blood containing sulphur. When these are absent from 
the food given to an animal, its blood cannot be formed. 
From this it also follows, that vegetable food will be b 
portionally nutritious and fit to sustain the vital procésses 
of the animal body, according to the amount of these 
ingredients contained within it. 
‘‘ There also exist certain families of plants, such as the 
Cruciferee, which contain peculiar sulphur-compounds 
much richer in that element than the vegetable consti- 
tuents of blood. Theseeds of Black Mustard, the Horse- 
radish, Garlic, Onions, and Scurvy-grass, are particularly 
marked in this respect. From all of these plants we 
obtain, by simple distillation with water, certain volatile 
oils, differing from all other organic compounds not 
containing sulphur, by their peculiar, pungent, and dis- 
agreeable odour. 
‘Those compounds containing sulphur are present in 
the seeds of all plants, as well as in the plants themselves ; 
and as they are particularly abundant in cultivated plants 
employed for animal nutrition, it is quite obvious that a 
substance containing sulphur is absolutely essential to the 
development of suc! F ds, in order to supply to 
them their proper proportion of this element.’”’ 
These are very remarkable statements, and require to be 
considered with great attention. The opinion, however, 
that sulphur is beneficial to plants is not originally Prof. 
Liebig’s ; he, on the contrary, so lately as 1842, adopted 
the erroneous views of Christison and Turner, and 
regarded the ‘‘ hydrosulphate of ammonia (sulphuret of 
ammonium) as a deadly poison to vegetables, the proper- 
ties of which we cannot change by dilution.”’ (Ed. 2, 
p- 195.) 1t was, however, proved experimentally by Mr, 
Edward Solly (Hirst Report of the Chemical Committee 
of the Horticultural Society, p. 9, June, 1842) that this 
was a mistake. “TI made use of the hydrosulphuret of 
ammonia, the very compound described by Liebig as being 
a ‘deadly poison ;’ but in place of killing plants, I found 
that in small quantity it produced decidedly beneficial 
effects : in some cases when it was applied to plants in an 
unhealthy state from the action of other substances, it had 
the effect of invigorating them, and of restoring their 
leaves to a healthy, green, and crisp condition. The 
plants with which these effects were best observed were 
the garden Lettuce and the common Windsor Bean. The 
solution of the hydrosulphuret of ammonia employed was 
prepared by mixing a saturated solution of the compound 
with fifty times its bulk of water: such a solution hada most 
nauseous disgusting smell, and contained of course a large 
quantity of sulphuretted hydrogen. The plants under 
experiment were selected from many, and were of the 
same age and size, and as far as possible in the same 
healthy state of growth. Some were watered with com- 
mon water, others with a dilute solution of hydrosulphuret 
of ammonia. At first only a few drops of the solution 
were given, but finding that this produced. little or no 
effect, the dose was increased, and as much as half an 
ounce a day, and sometimes even more, was given to each 
plant; it was found that those thus treated became 
stronger and sturdier, their leaves were of a bright 
deep green, the space between the nodes, or the distance 
from leaf to leaf, was shorter, and the stems were 
stronger, and the whole plant more flourishing than 
in those watered in the ordinary way, although all other 
circumstances were alike, and care was taken to place all 
under the same condition, by exposing them equally to 
air and light, and giving them the same quantity of water 
every day. Plants in a languid state from over-doses of 
nitrate of potash, or soda, or other saline manures, if not 
too much injured by their previous treatment, appeared 
to recover more rapidly when watered with the solution of 
hydrosulphuret of ammonia, than when merely treated 
with common water. In some of these latter cases a much 
stronger solution was employed than that already men- 
tioned, containing two drachms of the saturated solution 
of hydrosulphuret of ammonia in fifty of water, and of this 
eight drachms were given daily. For some time after thus 
watering the plants the earth retained a strong smell of 
sulphuretted hydrogen, and the water which drained 
through, when tested by a salt of lead, evidently contained 
a large quantity of that gas.’ And then he proceeds to 
point out the extreme improbability that a substance £0 
constantly evolved from decaying matter as sulphuretted 
hydrogen should not be the food of plants. ‘* Its presence 
in manures is well known and readily proved, but its pre~ 
sence in the air, in which it exists in exceedingly minute 
quantity, is less readily shown. We know, however, that 
it is constantly being formed on the surface of the earth, 
and we have evidence of its presence in the air by several 
effects, such as the tarnishing of some metals, and the 
blackening of white paint; these effects, which take place 
gradually and slowly, are principally occasioned by the 
presence of sulphuretted hydrogen and its compounds, 
more particularly the hydrosulphuret of ammonia, in the 
air. Lastly, if the vegetable kingdom is the great means 
of purifying the.air, and retaining it in a fit state for the 
respiration of men and animals, the absorption and decom- 
position of sulphuretted hydrogen by plants must constl- 
tute not the least important of their functions.’ 
We believe, too, but cannot lay our hands upon the 
passage, that Dr. Lankester had previously brought for- 
ward some evidence to show that sulphuretted hydroge® 
is not injurious to vegetation. é 
The source from which sulphur is obtained by plants A 
not the atmosphere, according to Dr. Liebig, but the 8017 
whence it is furnished by the decomposition of sulphates: 
“The air,’ he says (p. 68), ‘ cannot contain any ade 
stances in which sulphur is present, unless, indeed, We 
except minute and scarcely appreciable traces of sulphur 
etted hydrogen.’”” We confess our inability to understan! 
this. 3 
the author’s triumphant proofs, and yet it exists there a 
as minute and inappreciable a quantity as sulphurette 
hydrogen ; and we cannot comprehend why 
should not be thus supplied as well as the former- 
what, let us ask, becomes of the volumes of this 48 Coe 
tinually escaping from the surface of the soil? Are hubs 
to suppose that it is all consumed in forming sulphurets - 
Surely not. 
Next to sulphur stand phosphates in their importan 
to vegetation. ‘This, indeed, is not a new doctrine ; 0D ee 
contrary, their value was pointed out in the former & 6 
tions ; not, however, we think, so strongly a8 now: ¢the 
are rejoiced to find Prof. Liebig ranged on this side 0 é 
question, for it seems to us that if practical Agron 
: : is 
reat importance of phosphates. Nothing is moret” 
able than the action of the superphosphate of oe nad 
plants in gardens; no single agent that we have De nee 
employed can be compared to it. This probably seent 
from garden-soil being rich in all other substances ex a 
phosphoric acid, which is always largely carried 0 eae) 
but sparingly returned in the processes of garden cm iking 
The remarks of Prof. Liebig on this subject are 00 str 
to be omitted += ste.o8 
“In a former letter I showed you how great a Me the 
phosphates.is unavoidable in England, and referre tat i 
well-known fa¢t that the importation of bones restor 
amost admirable manner the fertility of the fields ex eT 
from this cause. In the year 1827 the jmportatio 
bones for manure amounted to 40,000 tons, 
estimated their value to be from 100,000. 
sterling, The importation is still greater at pres 
it is far from being sufficient to supply the waste, 
“ Another proof of the efficacy of the phosphates ™° 
oormeeraervemaicsanecmmaai 
=e 
