bought
and sold by the weight called a carat. This carat, whatever its precise
value, is always considered as divisible into four diamond or pearl
grains, but the subdivisions of the carat are usually expressed by the
vulgar fractions, one fourth, one eighth, one twelfth, one sixteenth,
one twenty-fourth, one thirty-second, and one sixty-fourth. The origin
of the carat is to be sought in certain small, hard, leguminous seeds,
which, when dried, remain constant in weight. The brilliant, glossy,
scarlet-and-black seed of Abrus precatorius constitutes the Indian rati, about three grains; the Adenanthera pavonina seed weighs about four grains. The seed of the locust-tree, Ceratonia siliqua, weighs on the average three and one sixth grains, and constitutes, no doubt, the true origin of the carat.
Another1 of the more notable of these weight-units used for precious stones and precious metals is the candarin, condorine, or can-tarai, also termed by the Chinese fun or fan, and by the south Indians a fanam, and
used all over the Indo-Chinese archipelago. This is by origin a large
lentil or pea of a pinkish color dotted with black, about double the
size of the gonj, and possessing the same quality of very
slight variability of weight when dried. It is probably a variety of
the same botanic genus or species as the Abrus precatorius. The
value when reduced to absolute standard became a subsidiary part or
sub-multiple of the weight of some local coin, rupee, or pagoda, or a
decimal fraction of some local tchen, as in China and Japan.
The following derivation of the word carat is given by Grimm: "Carat. Italian: carato; French: carat; Spanish and Portuguese: quilate; Old Portuguese: quirate, from Arabic qirat, and this from the Greek,κεράτιο»'."2
The
carat is not absolutely of the same value in all countries. Its weight,
as used for weighing the diamond, pearl, and other gem-stones in
different parts of the world, is given in decimals of a gram, by the
majority of the authorities, as follows :
