CALCINATION. 
CALCULUS. 621 
ate between corymbosa and arachnoidea, with re-! called calcination. This process, therefore, was 
spectively ochreous and dark, pale, bright brown, 
and dark flowers; and C. mzrabzlis, intermediate 
between pendula and insignis, with purple flow- 
ers. 
Persons who intend to grow calceolarias should 
purchase, at a nursery, a few sorts with flow- 
ers as nearly as possible to the globular form, 
no matter of what size, but with about three dif- 
ferent ground-colours, and three different blotch- | 
colours; and if they carefully rear these for one 
season, they will obtain abundance of seed, and, 
by means of these, a profusion of beautifully 
flowering plants. The herbaceous kinds at first 
yielded larger flowers than the shrubby kinds, 
and, on that account, acquired a temporary popu- 
larity ; but they are by no means so handsome as 
the shrubby sorts, and ought never to be selected 
when the latter can be obtained. 
The seed-pods should be gathered when turn- 
ing yellow, and should be laid to dry on a sheet 
of paper under a hand-glass. The seed may be 
sown, in early spring, on soil in seed-pans or in 
flower-pots well drained with crocks, and placed 
either under the glass of a garden-frame, or under 
a hand-glass in the greenhouse. When the young 
plants become large enough to be handled, they 
may be picked out, and reset an inch apart in 
other seed-pans; and may be allowed to grow 
there till they begin to incommode one another 
for space. They may then be potted in sixty- 
| sized pots, and placed to grow, in a medium state 
_ between draught and humidity, in either a pit 
| or a frame. 
If the green aphis attack them, it 
must be destroyed by means of a gentle fumiga- 
tion with tobacco-smoke. When the plants send 
their roots a little mattedly to the sides of the 
pots, they may be removed into forty-eight sized 
pots; and should they afterwards acquire con- 
siderable strength and bulk before flowering, they 
may be further removed into thirty-two sized 
pots. They will flower in spring; and all the bad 
and indifferent ones must be either thrown away 
as rubbish, or planted at a distance in the borders. 
The good or selected plants may be headed down 
in the pots, earthed up, and set to produce side 
shoots. If the earthing up be sufficiently high 
and porous, many rooted side shoots will speedily 
appear; and may be easily detached from the 
parent plants, and set to grow in separate pots, 
Other side shoots which spring out from higher 
parts of the stem must be detached as closely to 
the stem as possible, so as to be planted in pots 
without losing their bottom joint; and they should 
be covered with a bell-glass pressed into the 
ground to exclude the air, there to remain under 
shade and shelter till they strike root. 
CALCINATION. An action of heat upon a 
mineral similar to that which converts limestone 
‘| into quicklime. The old chemical name of quick- 
lime was calx; and this name was extended to 
any powdery metallic oxide which has an earthy 
aspect; and the process of forming a calx was 
very various in chemical character; for in the 
case of lime, it consisted in the expulsion of car- 
bonic acid ; and in the case of the oxidation of 
metals, it consisted in fixing oxygen. The word, 
as at present used, is simply a convenient popu- 
lar designation of all such applications of heat as 
reduce a compact body into a white powdery 
condition. Thus, we speak of calcined magnesia, 
calcined clay, calcined flints, and even calcined 
bones. But the calcined metals which were for- 
merly called calxes are now uniformly designated 
oxides. : 
CALCIUM. A simple or elementary body, of 
a metallic nature. It was first obtained in a 
separate state in 1808, by Sir H. Davy, by means 
of the action of voltaic electricity. It has so 
powerful an affinity for oxygen as nowhere to 
exist uncombinedly with it in nature, and as to 
be separable from it, or képt separate, only with 
extreme difficulty. It has been ascertained to be 
a white combustible metal, burning in contact 
with the air, with an intense white light, into 
lime. Combinations of calcium with various 
other elementary bodies occur; but, excepting 
the combination with oxygen constituting lime, 
they are wholly artificial. The practical value 
of calcium, therefore, whether in its natural oc- 
currences or in its artificial combinations, is 
wholly identified with lime. See the articles 
Lime and Catcareous Harta, 
CALCULUS, Any kind of concretion formed 
in any part of the body of an animal, and pos- 
sessing some resemblance, in shape or composi- 
tion, to a stone. Calculi are considerably varied 
in their manner of formation, much varied in 
their seat and effects, and exceedingly varied in 
their composition. Some appear to be formed 
by the action of chemical affinity, and possess the 
character of regular crystals; and a few of these 
may originate in the mere chemical aggregation | 
of minute particles of their elements held in so- 
lution in the animal fluids, while most seem to 
originate in the attachment of their first parti- 
cles to a fragment of some foreign body, such as 
a minute clot of blood or mucus, a minute piece 
of hair, or a minute speck of insoluble mineral 
matter. Many are formed by the mere mecha- 
nical amassment and consolidation of heteroge- 
neous, undissolved, mineral particles, around a 
nucleus, or by the mechanical segregation of 
such particles, by means of animal gluten; and 
some are formed by regular though diseased se- 
cretion, the absorbent vessels drawing off all the 
liquid elements of the matter which would have 
constituted a healthy secretion, and leaving the 
other elements in a sedimentary condition to 
harden into strong consistency. 
Salivary calculi, formed by concretion of mat- 
ters held in solution by saliva, frequently occur 
upon the teeth, beneath the tongue, and in the 
salivary ducts in the substance of the cheek. 
The substance, technically called tartar, which 
Sine Ges eee | 
