1802. ] 
quantity, as excellent promoters of vege- 
tation may be applied in fuch fuper- 
abundance as actually to deftroy it. No 
one would think of bringing this as an ar- 
gument againft their ufe; and yet it feems 
probable, that fome circumftances of this 
kind have had the effect of reviving with 
a few individuals, the old prejudices 
againft the ufe of falt as a manure. With 
how little reafon, the experiment I have 
mentioned (to which very many fimilar 
ones might, if neceflary, be added) is alone 
fufficient to prove. 
Ifthe fast is afcertained, that falt is a 
mott excellent manure, the immediate mode 
of operation may be of lefs importance. 
There is, however, always a fatisfaction 
in finding theory going hand in hand with 
practice ;, and this feems to be very parti- 
cularly the cafe here.—By the excellent 
experiments of the late Sir John Pringle, 
publithed in the ‘* Philofophical Tranfac- 
tions,’’ it is fully fhewn, that falt, when 
applied in {mall proportion, whether to 
vegetable or animal matter, inftead of 
preferving it, very much accelerates the 
putrefaction and decay of it; when added 
in larger proportion, itprevents this. 
Now as it is highly. probable, if not abfo- 
lutely certain, that -vegetable matter is 
not refitted to ferve, as food for other ve- 
getables, till it has been completely de- 
cayed, and has loftall vegetable character ; 
is thefe not reafon to believe, that the ef- 
feét of falt, when applied in fmall juan- 
’ tity, in accelerating putrefaction, may be 
the immediate caufe of the favourable in- 
fluence it exerts on vegetation? 
It is not, however, folely by the effect 
_ which falt has in producing an increafed 
growth of vegetables, that it is ufeful as 
a manure. Though experiments made by 
Wailerius and others have afcertained 
_ that it does not enter into the, immediate 
compofition of vegetables in its ftate of 
falt, yet it evidently appears to produce, 
in fome manner, a favourable influence 
on vegetable matter; and we find that 
thofe graffes or other vegetables to which 
falt has been applied, are not only better 
adapted to the tafte of animals, but are 
peculiarly bencficial tothem. ‘The far. 
mer, above-mentioned, remarked that his 
cattle were fonder of the grafs on that part 
of the field on which the falt-compoft had 
been laid, than of any other. “We well 
know -the vigorous vegetation in falt- 
marfhes, whether the brine is furnifhed 
by the fea, or by falt-{prings; and the al- 
moft immediate effect they produce on the 
health of animals, makes them the com- 
mon hofp tals for difeafed hor‘es and cattle, 
Hiftorical Statement of Galvanifm 193 
It is alfo found, that, when falt is added 
to hay and dried vegetables, thefe are 
not only much more relifhed by the cattle, 
but that they are by this addition ren- 
dered much lefs fubjeétto difeafe.. The 
Americans are fo well acquainted with 
this, that it is their conftant practice to 
mix falt with the food they give their 
cattle; and to fuch extent is this plan pur- 
fued, and fo much do they find the advan- 
tage of it, that more than one half the falt 
exported from this country to America, is 
applied to this purpofe. Though’ the 
price of falt is tothem about 2s. 6d. per 
bufhel, they find themfelves amply repaid’ 
for it. . 
(To be continued.) 
——a ie 
For the Monthly Magazine. 
HISTORICAL ACCOUNT Of the GALVANIC 
DISCOVERY, and of the PUBLICa- 
TIONS that have appeared on that 
important SUBJECT. 
(Continued from Page 506, of Vol. XII.) 
Gottingen, Dec. 7, 1801, 
HE writings of Mr. Votta on 
Animal Ele&tricity confit of two 
treatifes ; in the firft of which he relates 
his own experiments, after having previ- 
oufly given a moft interefting furvey of the 
Galvanic difcovery, compared with the 
more early conjectures of phyfiologifts on 
animal electricity. When he attempted 
to determine its quantity by a comparifon 
with artificial ele€tricity, he was induced 
to confder the frogs, prepared in the man- 
ner of Mr. GALVaANi, as the moft fenfible 
electrometers ; and he here again propofes 
his theory of animal electricity, in which 
he deviates from the ideas of Mr. Gal- ~ 
vani. He farther diftinguifhes four tages 
of death; the firft of which he. calls 
afphyxia, and the fourth total death, ap- 
proaching to putrefaétion. The fecond 
and third comprehend different degrees of 
decreafing vitality. The nature of every 
animal, as well as the manner of death, 
influences the duration of every degree of 
the ws-vitalis. The author has likewile 
produced Galvanic contrattions, by the 
coating of living and unprepared frogs, 
and alfo of feveral fifhes, without an 
previous preparation; a oectintanoe: 
moft probably, owing to the moift and 
thin {kin of thefe animals. In the fecond 
treatife Mr. Volta continues to relate his 
experiments on the effeéi of artificial elec- 
tricity in producing mufcular contraétions. 
By means of a {ma!l apparatus, which is 
deferibed by him, he endeavoured exactly, 
to determine the force of electricity that 
Ri is 
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Eso Doe 
mt. 
