Medical Botany. 47 
" is found, is considerably various, and especially, that its 
wh proximate principles, differ from every _ hitherto 
kstained from the vegetable kingdom. 
e second opinion is, that the Clavus is an exerescence 
produced by a7 sting, and deposition of the eggs of an 
insect. 
As there is no ‘0 analogy i in any —— between this arti- 
cle, and such excrescences as are demonstrably occasioned 
that the Clavus is occasionally found to be eaten by minute 
worms, and ~ small larve of insects, have been detected 
in it, whic ing preserved, afterwards hatched into 
moths, or buiasetines: hese occurrences are however too 
rare to establish the hypothesis, to eres they seem to have 
given rise, and our ee ne must be; that they 
are —, accidental. — 
third, (and only Fy sopt seisole ‘appears: to be well 
;) is that the Clavus is a parasitic Fungus, like the 
“ different sorts of blight, smut, &c. 
he correctness of this nH ic to arte to be fully estab- 
lished, by the following considera 
First. This article has, secs all the physical charac- 
ters, such as colours, form, taste, smell, &c. and even the _ 
casualties incident to Sclerotium, a genus of Fungi. This 
genus consists of small solid fungous bodies, of a rounded, 
oval, or elongated form, their interior substance hard, ocea- 
sionally almost as much so, as wood, sometimes a little 
fleshy, always white or inclining to white ; the outer skin 
in an early stage, is smooth, in a more advanced one often 
a little wrinkled, usually black, ‘sometimes of a dingy pur- 
ple, seldom yellow, or white, in several species, covered by 
a peculiar kind of dust, or efflorescence, of the same colour 
as the surface 
Second. it dies, like the several species of Sclerotium, an 
pia sti place of growth. Some of these, as we are i 
formed, are subterraneous, on the roots of mosses, or in id 
mass of tan, in bark-beds, in close damp places sereened 
from the light, as under moss heaps, or upon the surface of 
the ground under the droppings of cattle, on the nerves of 
altel stored under ground, upon the leaves and branches 
of plants that are beginning to decay, on the fading foliage of 
trees, on the rind of living fruits, on the receptacle of com- 
