CANADA-BALSAM. . 
tree tribe. It has recently been mixed up, 
by some botanists, with the lychnis genus; but 
must long, perhaps always, continue to be dis- 
tinct in the estimation of seedsmen and culti- 
vators. The common species, A. coronaria, has 
long been a hardy perennial ornament of our 
gardens, and was introduced from Italy before 
the close of the 16th century. It grows to the 
height of two or three feet, and carries a bright 
red flower from June till September. Two well- 
established varieties of it, alba and plena, carry 
respectively white and double flowers; but the 
latter variety is only about half as tall as the 
normal plant.—The umbelled species or Flower- 
of-Jove, A. Flos-Jovis, is a perennial, red-flow- 
ering plant, of about twenty inches in height, 
from Germany. ‘The smooth-leaved species or 
Rose-of-Heaven, A. celi-rosa, is an annual plant, 
of about a foot in height, and with flesh-coloured 
flowers, from the Levant. The githago or corn- 
campion species is the well-known weed Corn- 
CocKLE. 
CANADA-BALSAM. A balsam or turpentine 
obtained from the Balm of Gilead fir, Abzes bal- 
samea. It is light, yellowish, transparent, of an 
agreeable terebinthic odour, a slightly bitter and 
acrid taste, flowing like thin honey when fresh, 
but solidifying by time. Bonastre’s analysis of 
it gave, essential oil 18°6; resin easily soluble in 
alcohol 40:0; resin difficuitly soluble 33:4; elastic 
| resin 4:0; bitter extractive and salts 4:0. 
CANADA RICE,—botanically Zzania. A 
| small genus of aquatic grasses, of the olyra tribe. 
The water species, Zizania aquatica, abounds in 
almost all the shallow streams of north-western 
America, and affords, in its prolific produce of 
mild farinaceous seeds, abundant food for vast 
flocks of large water-fowl, and a considerable 
proportion of the ordinary food of the wandering 
tribes of Indians. It was introduced to Great 
Britain in 1790, and has been acclimated, not 
only in Middlesex, but in Ross-shire; and it has 
been regarded by some economists as probably a 
valuable addition to the number of our bread- 
corn grasses. It isan annual, and flowers from 
July till September, and usually attains a height 
of about six feet. See the article AccLIMATATION 
or Puants. The millet-like species, 7 maliacea, 
was introduced to Britain in 1816, and the float- 
ing species in 1824; and both of these are an- 
nuals, natives of North America, growing to the 
height of about four feet, flowering in July and 
August, and producing farinaceous seeds of im- 
portant economical value. Two other species 
have been scientifically described. 
_ CANAL. A canal, in navigation, is an artificial 
channel for transportation by water. The first 
inquiry in the project of such a work, accordingly, 
relates to the amount of transportation that will 
be accommodated by the route proposed, at some 
given rate of tolls: for the quantity will be in 
some degree influenced by that rate. If the pro- 
ject be a mere speculation, or investment of capi- 
CANARINA. 665 
tal by individuals for the sake of income, its ex- 
pediency will be determined by the nett amount 
of annual tolls it will probably yield; which ought, 
in this view of the matter, to be equal to the or- 
dinary rate of interest. But the general utility 
or public expediency of a project of this sort is 
not determined wholly by this mode of calcula- 
tion; for, in this view, we must look at the in- 
direct advantages, such as the increased value of 
lands on the borders of the canal, the increased 
profits of other works connected with or affected 
by the one proposed ; as in the case of the smaller 
branches of internal navigation in England, many 
of which are not very productive investments, 
but doubtless contribute to the large income of 
the great lines of transportation between the 
principal towns, as London and Liverpool, by in- 
creasing the amount of goods that pass along 
those lines. ‘To determine the general public 
utility of one of these smaller branches, there- 
fore, we must estimate not only the increased 
value which it gives to coal-mines, stone quar- 
ries, forests, &c., on its borders, but also its effects 
in enhancing the value of other canals. But a 
work of this sort may be, on the whole, of public 
utility, although an absolute income, in conse- 
quence of the investment, can nowhere be traced, 
but. only a reduction of the cost of some article | 
of general use, by means of a diminution of the 
labour, the number of days’ or hours’ work, ne- 
cessary to furnish the article, at any place. Thus 
the proprietors of the duke of Bridgewater’s canal 
are under obligation to supply the inhabitants of 
Manchester with coals at the rate of 4d. for 140 
lbs., which is a great benefit to the inhabitants 
of that town. 
of this work, which should be taken into the ac- 
count in estimating its public utility. Another 
beneficial consequence of any great improvement 
of this description, as well as those of other kinds, | 
often is to promote some species of arts: for in- 
stance, a canal may promote agriculture, horti- | 
culture, &c., by irrigation or opening a market, 
In determining on any canal project, then, as 
well as in estimating its utility, these various 
circumstances are to be taken into consideration. 
The motives, whether of public utility or private 
emolument, or a union of them both, being suffi- | 
cient to induce to the undertaking, the next 
things to be considered are, the obtaining of an 
adequate supply of water, the particular route to 
be taken, and the mode of construction. 
CANARINA. A small genus of ornamental, 
perennial-rooted, herbaceous plants, of the bell- | 
flower family. The bellflower and the smoothed | 
species, C. campanula and C. levigata, are natives 
of the Canaries, and were introduced to Britain, 
the former towards the end of the 17th century, 
and the latter in the year 1825; and both grow 
to the height of about three feet, and carry 
orange-coloured flowers from the end of autumn 
till the middle of spring. Sweet, speaking of the 
bellflower species, says, “It is very desirable as it 
This is one of the advantages | 
Se 
yf 
