1816.] Membranous Bodies of Animals. A25 
V. Hoof of the Horse. 
The hoof of the horse (either what is called the quick or the sole 
may be employed) possesses all the characters of horn. 
When it is distilled with water, a very fetid liquid is obtained, 
which contains no perceptible portion of solid matter. 
The only other difference which can be perceived is, that the in- 
soluble matter approaches much nearer to caseous albumen than 
to mucus. When subjected to putrefaction, it assumes exactly the 
nature of cheese. 
The hoof contains no true gelatine. I found no trace of acid in 
it; and it may be asked whether this substance has been really 
always wanting to the hoof, or whether it has been abstracted in 
consequence of the constant moisture to which the hoof is exposed? 
This may happen the more readily, as Nature has given to the hoof 
no portion soever of fat, by which it might be defended from the 
solvent power of the water. 
VI. Horny Excrescence of a Pigeon. 
This example, perhaps the only one kuown of a similar mon- 
strosity, is to be seen in the Royal Museum. ‘The pigeon, which 
was full grown, and of the size of a common pigeon, was sent from 
Nordhausen by Mr. Surgeon-General Gorcke. The excrescence 
had exactly the form of the born of a he-goat. It grew out of one 
side of the back, from which the tail feathers had fallen, and had a 
greater weight than the whole pigeon. 
The substance of this horn has a somewhat smutty wax-yellow 
colour. It is less transparent than horn ; and in respect of hard- 
ness, is intermediate between wax and horn. ; 
Through the goodness of Professor Rodolphi, I obtained a small 
portion, which we cvt from the hind end in such a manner that the 
loss would not be perceived by those who examined this extraordi- 
nary monster. 
By boiling in water, there was dissolved a small portion of gela- 
tinous mucus precipitated by infusion of nutgalls, and likewise 
traces of alkaline sulphate, muriate, and phosphate. 
Alcohol separated a fatty matter, as it did from the horns of 
black cattle. Cold water produced no effect. When incinerated, 
it left a very small portion of ashes, which contained an alkali, the 
above-named salts, phosphate of lime, and gypsum. The undis- 
solved portion of this horny excrescence, which amounted at least te 
94 per cent., possessed the properties of insoluble mucus, 
r 
to 
Vor, VII. N° VI. 
