388 A COMPENDIUM OF 
on either side of the body; this leech draws a 
larger amount of blood than the German worm. 
Both varieties taper toward each end, and are 
armed with three jaws, and in each jaw are to 
be found a double row of teeth. Leeches are 
propagated in shallow ponds, and feed upon the 
blood of the worn-out horses which have seen 
their best days. These poor beasts are driven 
into ponds, and allowed to remain until they 
are covered over with blood-sucking worms. 
The leeches are thus fattened for the market; 
and, indeed, the horse is only allowed to come 
out to be fed that he may have the strength to 
return and be bled to death by these blood- 
thirsty worms. Notwithstanding the propensity 
of the leech for this kind of food, they can only 
be kept in a state of health, for application to 
the human being, by preserving them in clean 
river water at a temperature not above 68° F. 
(20° C,), and it is usual to place in the water 
some pebbles, moss, charcoal, etc. Leeches 
when once applied should be placed by them- 
selves, and should not be again used for six 
months, A little table salt will cause the wor 
to disgorge the blood it has drawn. : 
The leech is used in medicine only for local 
blood letting. The leech found in this country 
is known as the hirudo decora, and will draw a 
little more than two fluid drachms of blood, 
whilst the European will extract as much as 
one fluid ounce. (For further account see Dis- 
pensatory). 
Ichthyocolla, Isinglass.—Obtained from the 
acipenser huso and other species of the Acipen- 
ser, and called by the Russians bulugo; belong- 
