108 
southern cultivator. 
fee, bakeYixs bread, boil his vegetables, and cook his meat ; 
and, if so, it is by no means wonderful that he is some- 
what slower in learning the value of heat in preparing 
food for his domestic animals, and in using it generally to 
effect those chemical and physical changes in soils which 
increase their fertility. Unable to see what takes place in 
roasted earth, and wholly unacquainted with the play of 
chemical affinities as modified by heat, farmers have often 
injured clay by over-burning it. Nothing is easier than 
to spoil coffee by the application of too much heat ; and 
to to burn bread or meat is not to bake either properly. 
These remarks are intended to illustrate the fact that there 
is an art in the use of fire for different purposes ; but that 
which applies to the due charring of clay is less than 
what is required to generate steam and apply it success- 
fully to the propelling of ships on the ocean or locomotives 
on railways. I regard the application of heat to the two 
last named purposes and its known power to extract iron 
from the crude ore, and caustic soluble lime from the com- 
paratively insoluble mountain rock, as true types of its 
equal availability to work the most important chemical 
changes in nearly all poor soils. Summer fallowing, 
which has been practised for indefinite ages, exposes till- 
ed earth, in a peculiar manner, to the influence of solar 
heat during the hottest part of the year ; but as the natur- 
al heat of the sun will not roast coffee nor bake bread, 
neither will it decompose the debris of felspar and mica 
in common clay fast enough greatly to improve poor land. 
Partial calcination does this under favorable circum- 
stances, by liberating potash from its before insoluble sili- 
cates. 
Sir Humphrey Davy, Liebig, and other eminent chem- 
ists have expressed the opinion that the charring of clay 
increases its capacity and aptness to absorb ammonia 
from the atmosphere, and in that way augment the fer- 
tility of impoverished fields. Dr. Voelcker, Professor of 
Chemistry in the Royal Agricultural College at Cirences- 
ter, England, wisely brought this explanation to the* test 
of experiment, and found that clay, in its natural state, 
imbibes from the air considerably more ammonia than it 
does when charred. Dr. Sprengel, a distinguished Ger- 
man agricultural chemist, taught his readers that heat 
probably converted the protoxide cf iron in clay into a 
peroxide, and decomposed water in the process, its hy- 
drogen combining with nitrogen to form ammonia, which 
was retained by the porous clay, and its oxygen uniting 
with the iron to change it into the red rust of that metal. 
The carefully conducted experiments of Dr. Voelcker, at 
the agricultural college, fully corroborated by experiments 
in the field, did not sustain this ingenious theory. In an- 
alyzing clays of the same locality and original composition, 
both before and after torrefaction, Dr, V. found that pro- 
perly roasted clay gave nearly four times more potash 
than it yielded to water before it was acted on by heat; 
and at the same time the carbonate oflime dissolved out by 
water acidulated with hydrochloric acid was considerably 
lessened by charring. Further researches proved that a 
double decomposition in the clay had taken place; lime 
that was before combined with carbonic acid had left it, 
and united with silicic acid, forming an insoluble silicate 
oflime. The potash that was before chemically united 
with silicic acid in an insoluble condition, and, therefore, 
not available as food for plants, being set free, united with 
the carbonic acid from the lime and formed common pear- 
lash or the carbonate of potash, which is a very soluble 
salt. 
These experiments and results teach us how unsafe it 
is to depend on the mere theories of great men, like Davy, 
Liebig, and Sprengel, where the momentous interests of 
agriculture are involved ; and how important it is to have 
agricultural colleges and experimental farms, where every 
scientific opinion entitled to investigation and every new 
practice in tillage or stock husbandry may be fairly tested 
by disinterested and competent persons. 
It will, I fear, extend this article to an inconvenient 
length if I undertake at this time to describe what agri- 
cultural clays are best for manure and the most economi- 
cal way of roasting them. If the subject, which contem- 
plates the improvement of many millions of acres in the 
United States, be deemed worthy of a small space in the 
Nationol Intelligencer, I shall be happy to present its 
readers with a summary of all the important facts devel- 
oped by the joint labors of cultivators and men of the 
highest scientific attainments. In this country we have 
yet to learn the wisdom of rigidly applying the inductive 
system of reasoning to the consideration of agricultural 
phenomena ; and hence, with all our mental culture and 
activity, we achieve next to nothing for the advancement 
of the science of agriculture. We accept for scientific 
truths the idle speculations of attractive writers on rural 
affairs ; and, finding them to fail when reduced to prac- 
tice, all book knowledge in farming and planting is 
brought into disrepute with the honest cultivators of the 
soil. D Lee, 
[m National Intelligencer. 
CHINESE SUGAR CANE. 
A correspondent of the Farmer tf* Planter remarks 
very sensibly : 
Mr. Editor: — No foreign plant has ever been introduced 
into the country which has swept it with such a “furor’^ 
as the “Sorghum Saccharatum.” 
Incredible has been its attributes. It was to makegood 
sugar, good syrup, good brandy, good beer, good flour, 
good dye-wood, and good paper, &c. It is one of our 
American peculiarities,^to always expect too much of a 
good thing. One virtue is never sufficient — it must claim, 
every one under the sun. We are optimists, and the mo- 
ment we find out that our sanguine expectations are not 
going to be realized, we get into a pucker, and denounce 
it all as humbug. 
Careful experiments, made by distinguished chemists 
during the last year, have settled the point that the Sor- 
ghum belongs to the family of grasses which secrete “glu- 
cose,” or fruit sugar — not crystalizable or cane sugar. 
The value of cane sugar compared to glucose, or grass 
sugar is as 3 to 1. We may give up, then, the hope of 
making sugar profitably. Carefully-conducted experi- 
ments, during the last year, however, have satisfied the 
writer that a very good syrup can be manufactured at the 
rate of 50 cents per gallon, and for even less, by the small 
farmer who is not entirely engrossed with the cotton crop. 
This will prove an inestimable blessing, bringing it with- 
in the means of almost every farmer owning a horse and 
an acre of ground, to provide their families with a luxury. 
But the great value of the Sorhum rests not in its syrup- 
making qualities, but in its being, for all animals, one of 
the cheapest, most delicious, and nutritious article of food ; 
particularly during a season of the year when a scarcity 
prevails. The period between the small grain harvest 
gleanings and the pea crop, is a very trying one ; and my 
friend, Maj. W. S. Lyles, asserts, from carefully-conduct- 
ed experiments, that land planted in sorghum will pay 
better in food for hogs, horses, mules, and cattle, during 
the autumnal months, than anything else. 
If a few acres of sugar cane — even on the best land a 
man has — will keep his stock out of his corn cribs until 
the pea fields are open, and start them into winter quar- 
ters in good order — fat, sleek, and contented — there is no 
telling its value. 
Don’t get alarmed, and cry, humbug ! but try it again ; 
try it as a part of the farm crop— as an investment, not as 
fancy a experiment— and you may rest assured it will pay. 
Glucose. 
