518 Transactions of tee American Institute. 



were each composed of others still smaller, which the limited power 

 of our instrument may prevent us from discovering. If such he the 

 structure of the hair of some animals, it is at least probable that the 

 hair of all others may have a similar conformation, although the fibers 

 of which they are composed may be too minute or adhere too firmly 

 together to permit us to separate or distinguish them." 



Chemical Composition. 

 The fact has long since been established that the chemical compo- 

 sition of nails, hoofs, horns, hair, wool, and even feathers, is substantially 

 the same. According to Henry, they are made up of an animal substance 

 resembling coagulated albumen and sulphur, silica, carbonate and 

 phosphate of lime, and oxides of iron and manganese. The similarity 

 of the odor of hoofs, horns and hair, perceptible when burned, is 

 within the experience of all. It is also well known that the horns of 

 cattle are made up of elongated fibers of hair, which will be obvious 

 to any one who will take the trouble to examine with the aid of 

 a microscope. Indeed, without this instrument the fact can be estab- 

 lished, as exemplified in the horns of the deer at certain stages of 

 the growth, and also those of the giraffe, on the surface of which 

 hairs can be distinctly traced. Other testimony may be found in 

 the circumstance, uniformly the same, that the horns conform in the 

 degree of their twist or curve to the hair or wool of the animals on which 

 they respectively grow. Thus, in the Angora goat and wild sheep of 

 the Rocky Mountains, the horns are, like the hair and wool they pro- 

 duce, comparatively straight, while the horns of the Saxon and Merino 

 sheep resemble the beautiful curves of their wool. 



Yolk. 

 This peculiar substance is so called, abroad, from its adhesiveness 

 and color, but with us it is termed gum, an appellation derived from 

 its glutinous properties quite as appropriate. It is apparent in the 

 fleeces of fine-wooled sheep, especially so in the Merino, at all seasons 

 of the' year, but very much so in the winter and spring ; and although 

 diffused through the entire fleece, yet such is its profusion in the 

 Merino, that it is observable in detached concrete particles resembling 

 ear-wax. According to the chemical analysis of Vauquelin, it consists 

 principally of a soapy matter, with a basis of potash, a small quantity 

 of carbonate of potash, lime in an unknown state of combination, and 

 an atom of muriate of potash. Its peculiar odor, well known to those 

 familiar with the fleeces of Saxon and Merino, is derived from the 



