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890 
ance, and character, to the common species.— 
The cow-parsley species, /7. panaces, is a peren- 
nial, and a native of Siberia, and was brought to 
Britain before the close of the 16th century ; but, 
in spite of its somewhat promising name, it pos- 
sesses little interest—The gum-bearing species, 
H. gumamiferwm, is a biennial, of somewhat medi- 
cinal pretensions, and was brought to Britain in 
1819.—About a quarter of a hundred of other 
species have been introduced, and six or seven 
more have been scientifically described ; but, ex- 
cept for some of them having a handsome appear- 
ance, they challenge the attention of no one but 
the systematic botanist. 
COW-POX. A well-known pustular disease of 
the teats of the cow. It has been proved to be 
| identical in physiological character with the 
small-pox of the human subject; and it fur- 
| nishes the means—the purulent matter of vacci- 
nation—by which the deadly power of that dis- 
ease over the human race has in modern times 
been broken. 
But another and far milder pustular disease 
| often attacks the teats of the cow, and has very 
often been confounded with cow-pox—indeed, 
previous to the discovery of the remedial energy 
of vaccination, was always confounded with it— 
but ought to be carefully distinguished. The 
pustules of this are neither so large, so round, 
nor so deep as those of cow-pox, nor have they 
the latter’s bluish colour; they appear like small 
vesicles, but often greatly vary in both size and 
form; they are filled, from the first, with puru- 
lent matter ; if rubbed off, they leave sore ulcers, 
which are sometimes not very easily healed; and 
if not molested, they soon form a scab, throw it 
| off, and are sound. These pustules are not con- 
tagious; and they may, in any instance, be rea- 
dily cured by proper washing and fomenting, or 
by the application of an ointment of lard, wax, 
alum, and sugar of lead, suitable for ordinary 
soreness of teats. 
The pustules of cow-pox have a bluish colour, 
a roundish form, and a little central depression ; 
they are filled, at first, with a thin, limpid, viru- 
lent fluid, and they afterwards and gradually 
become opaque and purulent ; each is surrounded 
by a broad circle of inflammation; they are easi- 
ly broken in milking; and when either broken, 
neglected, or roughly handled, they leave ulcers 
which are very foul and usually difficult to heal. 
These pustules, unlike the former sort, are evi- 
dently the eruption of a morbid virus in the 
blood, and, though local in manifestation, are 
strictly constitutional in character. At the time, 
or a little before the time of their appearing, the 
cow droops, refuses to feed, ceases to ruminate, 
is dull and heavy in the eyes, labours under con- 
| siderable fever, and almost ceases to give any 
| milk, 
She should not be bled, but ought to be 
freely purged, to receive a fever drink once or 
twice a-day, and to have her teats washed even- 
ing and morning with a lotion of Goulard’s ex- 
COW-POX. 
tract and camphorated spirit of wine, or with a 
diluted solution of the chloride of lime; and if 
the ulcers become very bad and obstinate, they 
may be treated in the same manner as garget. 
See the article Garcer, 
The pustules of cow-pox are exceedingly con- 
tagious, and have been known, from time im- 
memorial, to communicate cow-pox to persons 
who handle the teats of cows. A person infected 
from the teats has the pustules about the ends 
and joints of his fingers, and, if he have rubbed 
his face with his hands, he has them also on his 
cheek and lips; he becomes feverish, shivers, 
vomits, and is restless and excited; he suffers 
pain in the head and limbs; and in three or four 
days, his pustules burst, leaving ulcers which, in 
some instances, are foul and refractory. Persons 
thus affected were very long ago known to mul- 
titudes of farmers both in Europe and in Amer- 
ica, to be generally invulnerable to the attacks 
of small-pox; and hence the suggestion of the 
modern and most benign practice of vaccination. 
One inoculation was, for a time, believed to 
afford protection for life; but experience has 
proved that a second or even a third inoculation 
may, in some instances, be necessary. The prin- 
ciple on which vaccination operates is explained 
as follows by Liebig :— 
“The effects of vaccine matter indicate that 
an accidental constituent of the blood is destroy- 
ed by a peculiar process of decomposition, which 
does not affect the other constituents of the cir- 
culating fluid. If the manner in which the 
yeast of Bavarian beer acts be called to mind, 
the modus operandi of vaccine lymph can scarcely 
be matter of doubt. Both the kind of yeast here 
referred to and the ordinary ferment are formed 
from gluten, just as the vaccine virus and the 
matter of small-pox are produced from the blood. 
Ordinary yeast and the virus of human small- 
pox, however, effect a violent tumultuous trans- 
formation, the former in vegetable juices, the 
latter in blood, in both of which fluids respec- 
tively their constituents are contained, and they 
are reproduced from these fluids with all their 
characteristic properties. The precipitated yeast 
of Bavarian beer, on the other hand, acts en- 
tirely upon the sugar of the fermenting liquid, 
and occasions a very protracted decomposition 
of it, in which the gluten which is also present 
takes no part. But the air exercises an influ- 
ence upon the latter substance, and causes it to 
assume a new form and nature, in consequence 
of which this kind of yeast also is reproduced. 
The action of the virus of cow-pox is analogous 
to that of the low yeast; it communicates its 
own state of decomposition to a matter in the 
blood, and from a second matter is itself regen- 
erated, but by a totally different mode of decom- 
position ; the product possesses the mild form, 
and all the properties of the lymph of cow-pox. 
The susceptibility of infection by the virus of 
human small-pox, must cease after vaccination, 
