BORT CARBONS, ETC. 335
ter
in the various species were not so constant as those of the former.
Kuara is a native African name for a species of Erythrina or coral
tree. The Greek κ^άπο» refers to the horn-like shape of the
fruit pods of the ceratonia, whereas " carat" is an obsolete English
name for the seeds. It seems probable that the seeds of both had an
influence in establishing a certain amount of mass as a quotable weight
which finally became known definitely as the carat. According to
writers of the seventeenth century, the carat was divided into four
grains, but they were not the ordinary grains of standard weight, nor
do they appear to have been reckoned as equivalents of any standard
weights outside of the trade. In the eighteenth century, 150 carats
were considered equal to about one ounce troy. In the early part of the
nineteenth century, the weight was established more definitely in
England as 151-1/4 to 151-1/2 carats to the ounce troy. The weight
decreased in value evidently as the things it weighed became more
generally recognized as precious. The Greek weight Ktpartov (ceratium)
and the Roman siliqua were a little heavier than our present carat
(3,174 grains troy), as they were equivalent to 3-1/2 grains.
Whatever
the origin, or however it may have been used in India or by Indian
merchants in their trading with foreigners within or without the
borders of their own land, the weight does not appear to have been
adopted in India as a standard. Early travelers in India found the "
rati " or " ruttee " and the " mangelyn," to be the weights generally
used. The rati also had its origin in a seed; that of Abrus precatorins
(Linn). Evidently weights bearing the same name varied
