156 



INTRODUCTION. 



the central stem, and varying, in number, size, and degree of projection, 

 in the wool of different animals. In some instances these scales are 



159 



i i>*6>'i-- i t ' 

 A fibre of long Merino wool, viewed as a trans- 

 parent object. 



The same, viewed as an opaque object. 



pointed, in others round. In the wool of the Bat (fig. 160), these cir- 

 clets are so decided as to produce the appearance of a series of cups, 

 placed one in another, and having indented edges. Though hair is 

 covered with scales, or rugosities, it has no serrations, or tooth-like pro- 

 jections ; the hair of the Tiger is covered with scales, like those on the back 

 of a Sole ; while, in the wool of the same animal, the serrations are distinct 

 and numerous, as they are, also, in the wool of the Bear, and of the Italian 

 Wolf-dog. The human hair, as ascertained by Mr. Gill, is of a cylindrical 

 form, and covered with scales, or rugosities, but without serrations.* 



The engravings (figs. 158 to 169), from Mr. Youatt's work, serve to 

 illustrate the microscopic characters, here detailed, by which hair and 

 wool are respectively distinguished. 



The wool of the Rabbit (fig. 161) is fine, with sharp, angular serra- 



160 



The wool Of a Bat, as exhibited by th 

 microscope. 



The wool of the Rabbit, opaque. 



tions, to the number of 2880 in the inch, " being 160 more than in the 



highly- valuable and felting Saxon wool." The fibre, however, has fewer 



curls. The hair (figs. 162, 163) varies from ^ to ^5 part of an inch 



162 163 



The hair of the Rabbit, transparent. 



The hair of the Rabbit, opaque. 



in diameter, and is covered with a scaly incrustation, but cannot be said 

 to be serrated. 



* Dr. Goring (see Brande's Quart. Jour., 1826, p. 433) describes the appearance of the hair of the 

 human head, beneath the lens of a microscope, as being " indented with teeth, somewhat resembling 

 those of a coarse, round rasp, but extremely irregular and rugged ; these all incline in one direction, 

 like those of a common file ; viz., from the origin of the hair toward its extremity." " It is singu- 

 lar," says Mr. Youatt, " that although nine years have passed, and the microscope has been consider- 

 ably improved, since Dr. Goring observed this structure of the hair, and almost every one, who pos- 

 sessed an instrument of much power, has been eager to gaze on this new discovery, no person has 

 been so fortunate as to detect a single serration on its edge." A truly serrated surface is, according to 

 Mr. Youatt, the character of wool only. 



