146 THE SHEPHERD'S MANUAL. 



hairs of the cow and calf are so unlike the majority of those of 

 the wool-bearing animals in their size and shape, that it might 

 seem easy to make the distinction. They are much shorter, much 

 thicker at their base, taper rapidly towards the point ; the medulla 

 occupies a larger proportional part of the whole hair, and the free 

 edges of the scales of the cuticle, which are so disposed as to form 

 from twenty to forty imbrications to the Viooth of an inch, lie 

 quite smoothly upon the surface of the hairs, so that their con- 

 tours, as seen under the microscope, closely approximate continu- 

 ous lines. These characters are so well marked that the coarser 

 hairs of the cow and calf can readily be distinguished from the 

 woolly hairs of any of the wool-bearing animals. On the other 

 hand, however, the majority of the woolly hairs of the sheep offer 

 a combination of characters which are never found in the hairs of 

 the cow and calf ; namely, each of these hairs extends from half 

 an inch to several inches in length without any medulla, and 

 without perceptible taper. They present at frequent but irregular 

 intervals, well-marked, one-sided, more or less spirally arranged 

 thickenings of the cortical substance, which give to the wool its 

 curly character. The mean diameter of each hair varies from 

 Veooth to the Yioooth of an inch, or even less ; and the scales of the 

 cuticle are so arranged that their free edges project somewhat, 

 forming well-marked imbrications, of which usually from fifteen 

 to thirty can be counted in the Viooth of an inch. The fine hairs 

 of the goat and kid, from the Yioooth to the Yaoooth of an inch or 

 less in diameter, also run from half an inch to an inch or more, 

 without perceptible taper, without medulla, and are clothed with a 

 cuticle resembling that of sheep's wool, but are almost, or alto- 

 gether, devoid of the irregular thickenings of the cortical sub- 

 stance which characterizes the latter. Similar hairs are found in 

 certain deer, and some other animals, but never on the cow or 

 calf." The report is accompanied by highly finished heliotype 

 illustrations of samples of different kinds of hair and wool. 

 The chemical composition of pure, dry wool, is as follows : 



COMPOSITION OF PURE WOOL. 



Carbon 49.25 per cent. 



Hydrogen 7.57 " " 



Nitrogen 15.86 " " 



Sulphur 3.66 " " 



Oxygen 23.66 " " 



100.00 " " 



The fibers of fine wool are very closely seated upon the skin. 

 The pure Merino has from 40,000 to 48,000 fibers on a single 



