OBSERVATIONS ON LEECHES. 
311 
not only difficult to cleanse the vessel under such circum- 
stances, but that in doing this and replacing these substances, 
which must be done at least every three weeks in summer, 
a number of leeches are wounded and crippled. 
The vessel which I employ for preserving large quantities 
is constructed of beech-wood, and is about 4 feet high and as 
many in circumference. In it is placed grass turf, arranged 
on shelves one above the other for three quarters of its 
height, and in a funnel-shaped form, so that the water may 
easily run off. It contains a false bottom, below which is a 
cock, with an arrangement to prevent the leeches from es- 
caping, through which the water may be drawn off. The 
lid consists of a wooden frame, with varnished iron-wire 
net-work with rather wide meshes. The inside of this frame 
is moistened from time to time with sulphuric acid, which 
prevents the leeches from creeping on the sides of the vessel. 
The acid does them no harm, but appears on the contrary to 
prevent their dying so easily, and moreover to render them 
sooner fit for use. In a vessel or pail of this kind from 3000 
to 5000 leeches may be kept. 
With respect to the breeding of leeches, I obtained in au- 
tumn from 4000, kept during last summer in a vessel of the 
kind described above, about 700 young leeches. 
One of the greatest inconveniences with leeches is when 
they refuse to bite, and although considerable attention has 
been paid to this subject, most of the means advised under 
such circumstances are attended with little success. Martius, 
in his 'Zoology,' mentions several, one of which I have found 
to do good service. As it is always to be had, it deserves 
to be better known. When weak beer is warmed to about 
100° Fahr., and the leeches left for a few minutes in it, they 
suck with the greatest avidity. Those which will not suck 
after this treatment I have almost always found to be ill. — 
Lond. Chem. Gaz., Archiv der Pharm. 
