462 INDIAN CYPRINID&. 
A solution of this substance mixed with Canadian balsam and spread 
on black silk forms the useful article called court plaster. A few grains 
of isinglass boiled in milk forms a most nutritious food, which is given 
medicinally. 
Ignorant of its abundance in certain fishes of the Hoogly, that used 
by the English residents in India is still imported, probably at an expense of 
about 800 Rs. per maund,* while the same thing is collected in abundance 
and shipped to China from the Calcutta river.} 
Ten grains of this substance is sufficient to give the consistency of jelly 
to a pint of water, and as it keeps good in a dry state for any length of time, 
we may imagine its value as a portable food, and what its importance might 
be in times of scarcity, since one pound avourdupois, at the above rate, would 
afford a nutritious meal to 1560 persons. 
Whether it be used in times of scarcity in China I do not know, 
but probably it is collected and stored to meet such occasions, since Dr. 
Lumqua—an honorary member of this Society—a Chinese Physician, long re- 
sident in this city informs me that the Bengal jish-sago procured from Poly- 
nemus sele, Buch. is known throughout the empire, and that nothing could 
surpass his surprise on his arrival nearly twenty-five years ago in Calcutta, 
when he found that with the exception of his own countrymen who carried 
on the trade, no one appeared to know or care anything whatever for the 
article in question, and as no one could describe the fish, the same igno- 
rance continued up to within the last few months to prevail on the sub- 
ject. The advantage, however inconceivable of an abundant supply of 
any substanee, a single maund of which would afford a nutritious meal 
to upwards of one hundred thousand persons, could only be felt occasionally. 
but the intrinsic value of the article in all the common conveniencies of 
* It is retailed in Calcutta at a much higher rate. 
+ See Journal of the Asiatic Society for March 1839. 
