The above engraving represents one of a breed of pigs imported into this country by Hon. Daniel Webster, 
from Portugal. They arrived at New-York about the time of Mr. W.’s death, and were passed over by his 
heirs, to E. W. Kimball, Esq., of Long Island. Some of this importation are now in the hands of S. W. Jew¬ 
ett, Esq., of Middlebury, Vt., and A. E. Beach, Esq., of New-York, to whom we are indebted for the engrav¬ 
ing. They greatly resemble the Chinese, except in color, these being of a dark red. 
; 1 " - - - - ’ --- ' 
Plaster of Paris as a Fixing Agent. 
Messrs. Editors —In a previous number of the 
Co. Gent,., (Yol. 3, p. 327—May 25, ’54.) I detailed 
some experiments made upon gypsum (sulphate of lime) 
and carbonate of ammonia, showing that they will de¬ 
compose each other when 'dry, and from this inferring 
that the use of the former as an ingredient of compost 
heaps, to retain the latter liberated by decay, was 
founded on truly scientific principles. 
During the summer I have extended these # investi- 
gafcions, and experiment has demonstrated what was be¬ 
fore inferred. 
A few ounces of gypsum or sulphate of lime, (dry, 
but not burned,) was exposed to the fumes and gasses 
arising from the vault of a privy, for a few weeks, and 
then carefully examined, when it was found to contain 
a sensible amount of sulphate of ammonia which had 
arisen from the absorption and decomposition of the 
carbonate of ammonia, given off from the decaying 
night-soil. The amount was small, but the conditions, 
of the experiment were such that a large amount could 
not have been expected. Yet this small amount prov¬ 
ed the theory correct. 
Another experiment, still more decisive, was tried. 
Some gypsum was spread upon a common plate; this 
set upon a pile of horse-stable manure, a small box in¬ 
verted over it to prevent any manure coming in con¬ 
tact with the gypsum, and the whole covered with the 
manure, which was accumulating from day to day. 
The pile was continually undergoing decomposition and 
decay, attended by some heat. At the end of some 
weeks, the gypsum was taken out, exposed to the air 
a day or two, and then chemically examined. It was 
still nearly dry, that is, not wet, and contained a very 
notable quantity of sulphate of ammonia and carbo¬ 
nate of lime, proving most decisively that as carbonate 
of ammonia was generated by the decomposition and 
decay, it was absorbed and decomposed by the gypsum, 
and retained in the form of the sulphate of ammo¬ 
nia. 
It has long been known and recognized that such 
decomposition took place whenever these materials were 
in actual contact, and dissolved in water, but many 
have denied that it would take place when dry, and 
hence that gypsum was of no use in a compost, or mix¬ 
ed with barn-yard manure, to fix the ammonia, for in 
such cases it was not dissolved, but merely moistened 
generally. The experiments published last spring, and 
especially these now mentioned, prove that it will re¬ 
tain it, partially at least. When they are mixed in 
piles, the conditions for the decomposition are much 
more favorable than in the experiments made, for then 
they are in contact, and moistened, and the instant 
the one is liberated by decay, the other decomposes 
and retains it. 
It is unnecessary here to enumerate in detail the ap¬ 
plications, many of which have long been used without 
any doubts of their efficacy, by those reaping the ad¬ 
vantages. It forcibly suggests the use of gypsum with 
