78 A HALF-HOUK WITH TITR 



CHAPTER YI. 



A HALE-HOUR WITH THE MICROSCOPE 

 IN-DOORS. 



For amusement and instruction with the Micro- 

 scope, we need scarcely stir out of our rooms. The 

 very hairs on our head may be made objects of 

 II interesting investigation, and especially if we com- 



pare them with the hairs of other animals, and the 

 appendages generally of the skin. The fine outer 

 coating of the skin is composed of minute scales, 

 which are flattened cells, and may be easily ob- 

 served by scraping a portion of the skin on to 

 a glass slide with a drop of water on it. The nails, 

 the hairs, and other appendages of the skin, are 

 composed of the same kind of scales, or cells. 

 These cells are developed in little pits, or follicles, 

 from which the hair is projected, as it were, by 

 their growth from below. Under a low power the 

 cells of the human hair cannot be observed. It pre- 

 sents, however, a well-marked distinction between 

 the outside, or cortical layer, and the interior, or 

 puljx The latter, by a high power, especially if 

 the hair has been first submitted to the action of 

 sulj^huric acid, will be found to contain cells more or 

 less spherical, whilst the former contains cells more 

 or less flattened. These project a little beyond the 

 edge of the hair, so that its sides are not quite 

 smooth, as seen at figure 184 in plate 7. By 

 placing a hair between two pieces of cork, fine 

 transverse sections of it may be made by means of 

 a sharp razor. If these are put under the Micro- 



