COWSLIP. 
for the substance to the presence of which this 
susceptibility is owing has been removed from 
the body by a peculiar process of decomposition 
artificially excited. But this substance may be 
again generated in the same individual, so that 
he may again become liable to contagion ; and a 
second or a third vaccination will again remove 
the peculiar substance from the system.” 
COWSLIP, —botanically Primula veris. A 
low, perennial, herbaceous, beautifully-flowering 
plant, of the primrose genus. It grows naturally 
in the meadows and moist pastures of Great 
Britain; and is one of the most handsome and 
loved of the wild plants of our country. It is 
strictly similar to the common primrose in root, 
leaf, and form of flower, but differs and is readily 
distinguishable from it by its flowers being pro- 
duced in bunches at the top of the footstalk. It 
is generally regarded as quite a distinct species 
from both the primrose and the oxlip,—Primula 
vulgaris and Primula elatior ; but all the three, 
together with several intermediate varieties, have 
| been repeatedly obtained from the seed of a sin- 
gle plant; and as to the innumerable and very 
beautiful varieties and subvarieties, single, semi- 
double, and double, endlessly diversified and va- 
riegated in the tints of their petals, and in some 
instances coloured in their calyxes—as to these, 
which adorn every garden under the popular and 
comprehensive name of polyanthuses, and which 
have every shade and character of colour, from 
the simple yellow of the plain wild primrose, up 
to the most elaborate rivalry with the finest and 
most gorgeous auriculas, we cannot possibly re- 
gard them otherwise than as the mingled off- 
spring of the primrose, the oxlip, and the cow- 
slip,—following in some instances the exact type 
of the primrose, and in others the exact type of 
the cowslip, but aggregately so blended as to be 
really a congregation of undistinguishable hy- 
brids, 
The common wild cowslip is yellow in its flow- 
;| ers, and much rarer in occurrence than the wild 
primrose; and it blooms in May and June. It 
abounds most on clayey and chalky soils. Its 
old names were paicle and paralysis; and its re- 
puted virtues, for both economical and medicinal 
purposes, were numerous. Its flowers have a 
fine odour, and are used to impart fragrance to 
preparations called cowslip wine and balsamic 
tea; and its roots have an agreeable perfume, of 
a carminative and gently aromatic character, 
and are used for improving the flavour of malt 
liquors. The leaves are sometimes used in the 
kitchen; and both they and the flowers are 
greedily eaten by cattle. The chief of the medi- 
cinal powers anciently ascribed to the cowslip 
was that of an anodyne; but this is either a 
sheer fancy, or exists only in the pleasant look 
and odour of the flowers. 
COWSLIP (Ammricay). See American Cow- 
SLIP. 
COW-TREE,—botanically Galactodendron. An 
COW-TREE. 891 
evergreen, tropical, and remarkably economical 
tree, of the nettle tribe. It constitutes a genus 
of itself, and takes for its specific name wile or 
the useful; but it is very closely allied to the 
genus brosimum. It grows wild on the rocky 
declivities of the northern Andes; and was in- 
troduced, in 1829, from the Caraccas to Great 
Britain. Its roots are thick and ligneous, and 
scarcely enter the crevices of the rock on which 
they grow; its stem usually attains a height of 
about 50 or 60 feet, but is sometimes 7 feet in 
diameter and considerably upwards of 100 feet 
in altitude; its branches have, during several 
months of the year, an appearance as if dry and 
dead; and its leaves are fan-shaped, and, in 
spite of long droughts in every year, are strictly 
perennial. When an incision is made in the 
trunk, particularly about the time of sunrise, a 
fluid is copiously discharged which has all the 
appearance and many of the properties of milk, 
and which the natives eagerly collect in vessels 
to be used in the same manner in which cows’ 
milk is used in Europe. This fluid, when re- 
ceived into vessels, becomes yellow, and thickens 
at the surface; it is not so thin as the milk of 
animals, yet mixes easily with water; and when 
boiled, it forms a thick pellicle on the surface, 
but does not, even with the aid of acid, form any 
coagulum. “The milk obtained by incisions 
made in the trunk,” says Humboldt, “is gluti- 
nous, tolerably thick, free from all acrimony, and 
of an agreeable and balmy smell. It was offered 
to us in the shell of the trituros or calabash tree. 
We drank a considerable quantity of it in the 
evening, and very early in the morning, without 
experiencing the slightest injurious effect. The 
viscosity of the milk alone renders it somewhat 
disagreeable. The negroes and free labourers 
drink it, dipping into it their maize or cassava 
bread.” Mr. Lockhart, of the Trinidad Botanic 
Garden, bears a similar testimony, compares its 
taste and consistency to those of sweet cream, 
and says it is used by the inhabitants wherever | 
it is known. M. Boussingault examined the 
milk fresh from the tree, and made analyses of it 
on the spot; and he says: “ By the mere action 
of heat, it is separated into two distinct por- 
tions,—the one fusible, of a fatty nature,—the 
other fibrinous, and presenting all the characters 
of animal substances. If the evaporation of vege- 
table milk is not carried too far, the fatty matter 
may be obtained unchanged; it then possesses 
the following properties:—it is white, translu- 
cent, sufficiently solid to resist the impression of 
the finger; it fuses at 140° Fahrenheit; boiling 
alcohol dissolves it completely ; it is equally sol- 
uble in potash. The fibrinous matter presents 
all the characters of fibrine, obtained from the 
blood of animals; for this reason we have called 
it fibrine. In fact, when put on a hot iron, it 
swells up, fuses, and becomes carbonized, exhal- 
ing the odour of grilled meat. Treated with 
weak nitric acid, it gives out nitrogen gas; by 
