770 
if 
is produced during trituration is easily laid by 
sprinkling it with water. When the pulverized 
charcoal is to be used in flower-pots, in furrows, 
in seed-pans, or in seed-beds, it is sprinkled on 
the surface and incorporated with the spade or 
with the watering-pot. ‘This may also be done 
after the plants have germinated, and are 2 or 3 
inches high, according to the nature of the spe- 
cies. In sown fields the same method is followed 
in applying it as with manure. Therefore, in 
treating ground burnt up by the sun, according 
to the opinion of the Abbe Piccone, it is laid on 
the ground towards spring, when French beans 
are to be sown, to preserve them from drought ; 
to these succeed common beans, and afterwards 
wheat or any other grain without manure. In 
soils less arid, the rotation is begun with pota- 
toes, hemp, buckwheat, and wheat. In every 
case the seed should be used sparingly. On arti- 
ficial meadows charcoal dust is sprinkled in 
spring on the surface, as is practised with chalk 
and lands containing saltpetre. As to the quan- 
tity, the Abbé Piccone computes about an equal 
weight between charcoal and woollen rags, skins, 
and even scrapings of bones: a rubbo (about 18 
Ib. avoirdupois) of charcoal to two of new urine ; 
three of night-soil well digested; four of fresh, 
and six of common manure. After this, he ad- 
vises, for olive-grounds, vineyards, orange-gar- 
dens, or orchards, to allow an interval of four 
years for the first time, five for the second, and 
six for the third, and so on between every man- 
uring, taking care always to increase the quan- 
tity according to the growth of the trees.” 
About six or seven years ago, M. Lucas, a very 
talented assistant in the botanic garden of Mu- 
| nich, accidentally discovered that some hothouse 
plants, whose roots found access to charcoal ash- 
es, displayed an extraordinary vigour of growth; 
and he and other distinguished cultivators after- 
wards made several series of careful and multi- 
tudinous experiments, the results of which ap- 
peared to show that charcoal roots cuttings and 
slips of some plants which can with difficulty, if 
at all, be rooted by any other known means,— 
that it facilitates the rooting of cuttings and 
slips of many plants which are usually rooted in 
ordinary soils,—that it exerts a healing or resto- 
rative power upon many sickly plants,—and that, 
in a state of mixation with the several kinds of 
ordinary soil, it acts as an excellent general ma- 
nure, and can be made greatly conducive to the 
most common purposes of both field and garden 
cultivation. Dr. A. Buchner, Sen., writing in 
the ‘Garten Zeitung, makes pointed reference 
to these “numerous experiments and observa- 
tions,” pronounces them to be “very important 
| contributions, not only to vegetable physiology 
and dietetics, but also to the founding of a vege- 
_ table therapeutic system,” and makes a very 
clear scientific statement, though necessarily but 
a theoretic one, of the manner in which he sup- 
poses the charcoal to produce its beneficial effects. 
CHARCOAL. 
The following is the most important portion of 
his statement :— 
“1. Absorption of Light, and Generation of 
Hleat.—lt is well known that bodies receive the 
light of the sun the more perfectly, the darker, 
duller, and looser they are, and that the conse- 
quent development of heat is in proportion to 
this absorption of light; hence, a black light soil 
is, under the same circumstances and relations, 
much more favourable to vegetation than a light- 
coloured, grey, heavy earth. Heavy clayey soil, 
with a deficiency of humus, is less suitable to ve- 
getation, inasmuch as it soon loses its porosity 
through rain and snow, and assumes a smooth 
surface, by which it is prevented from absorbing 
air and light, and generating heat. Hence agri- 
culturists justly name these clayey soils, which 
are deficient in humus, cold soils. As charcoal 
dust is one of the darkest, dullest, and most por- 
ous of bodies, it must, on account of its peculiar 
capacity of receiving the sun’s light and chang- 
ing it into heat, be particularly favourable to 
vegetable life. 
“2, Absorption of Atmospherical Air.--Among all 
porous bodies that have the capacity of absorbing 
gases and vapours, charcoal has been proved by 
numerous experiments to hold the first rank. If, 
therefore, clayey soil, deficient in humus, is in | 
general less suitable to the growth of plants than 
rich loose garden mould, the reason lies, not only | 
in the latter receiving more light and creating 
warmth, but also in its more readily condensing, 
by its greater porosity, the constituent parts of 
the atmospheric air, and consequently supplying 
oxygen, nitrogen, and carbonic acid gas for the 
nourishment of the spongioles. We come here 
to a very important point, the nourishment of 
plants, which I cannot slightly pass over in elu- 
cidating the theory of the effects of charcoal in | 
this respect. Modern vegetable physiologists are, 
for the most part, of opinion, that plants can re- 
ceive no solid nourishment from the earth; that 
is, that every thing that they can assimilate must 
be in a liquid and gaseous or vapoury state. Ifwe, 
therefore, meet with siliceous earth, chalk, mag- 
nesia, oxide of iron, in short, such substances in 
plants as could only be received from the soil, we 
may always consider it certain that these sorts of 
matter can only be absorbed by the roots in pro- 
portion as they are in a fluid or dissolved state 
in the soil. These sorts of matter, and particu- 
larly the different organic salts which we find in 
the ashes of vegetables, are not actually to be 
considered sources of nourishment, but stimulants 
to assist in digesting, as salt and spice are to the 
higher animals and man; we also not unfre- 
quently observe, that a superfluity or mixture of 
certain inorganic substances in the soil, prejudi- 
cial to certain families and species of plants, is 
the cause of disease when this inorganized mat- 
ter is in a dissolved state, and capable of being 
absorbed by them.—If we analyze the nourish- 
ment of plants, wé shall find it is only the con- 
