THE HAIR. 59 



and sulphuretted hydrogen which we see developed on the macro- 

 chemical treatment of these tissues with even very dilute alka- 

 lies, are not derived from the main substance that is to say, the 

 cell-membranes but must originate in the cell-contents, or what 

 is still more probable, in the connecting medium. If therefore a 

 sulphamide of protein actually exists, it must be sought for in the 

 tissue connecting the cells of the horny tissue, or, at all events, in 

 their contents. 



Although this connecting medium or true intercellular sub- 

 stance of the horny tissue can certainly not be detected by the 

 microscope, it cannot possibly be wholly wanting ; for inde- 

 pendently of the fact that some of the above-described micro- 

 chemical reactions testify to its existence, it would not be easy to 

 understand how the cells formed in the mucous layer the true 

 matrix of this horny tissue and driven forward, and gradually 

 drying during the growth of the tissue, could entirely divest them- 

 selves of the adhering plasma. The cell-contents and the inter- 

 cellular substance, the cell-wall and the nucleus, must stand in 

 the active living cell, not only in a physical, but also in a chemical 

 antagonism ; and cannot possibly so far lose this diversity of cha- 

 racter in the dried, atrophied, or disintegrated cell, as to form a 

 chemically homogeneous substance, a simple sulphamide com- 

 pound. 



These remarks are by no means intended as an attack upon 

 Mulder, whose labours, even on this subject, are very valu- 

 able. 



THE HAIR. 



IF we are scarcely able to arrive at a clear or distinct view of 

 the chemical relations of the morphological elements of the com- 

 paratively simple horny tissues, we are still less able to do so in 

 reference to the far more complicated tissue of the hair. On 

 examining a hair, we find that there are at least three morpho- 

 logically different substances brought under our notice ; namely, 

 the cuticle, the cortex, and the medullary substance. 



The cuticle of the hair consists of plates arranged in the 

 manner of tiles, one above the other ; these are rendered more 

 visible, according to Bonders and Kolliker, by the use of those 

 reagents which cause the cortical substance of the hair to swell, as, 



