HORNY MATTER. HH1 



The matter of the middle coat of arteries is therefore repre- 

 sented by C 48 H 38 N 6 O 16 ; which is equivalent to J atom of pro- 

 tein plus 2 atoms of water (Scherer). 



Membranous and compact horny matter. This substance is a 

 product othe organism not subject to reabsorption, and differs 

 in that respect from all the others yet considered. 



The membranous horny matter constitutes the epidermis, in 

 particular, or outer skin, and also the epithelium in its different 

 modes of formation. The scaly epithelium which forms the 

 inner surface of the blood and lymph vessels, the inner surface 

 of many mucous and serous sacs, &c. The columnar epithelium 

 which forms the surface of the intestinal canal, as well asrthe 

 surface of the passages from most glands. The ciliated epithe- 

 lium which forms the surface of the mucous membrane of the 

 organs of respiration, &c. 



The compact horny matter constitutes hair, horn, nails, claws, 

 &c. 



I. M. Scherer's analysis of membranous horny matter was 

 made upon the epidermis of the sole of the foot. It was first 

 thoroughly washed with water, then boiled in alcohol and 

 ether. Dried at 212, and then burnt, it left 1 per cent of earthy 

 ashes. Its composition, by two analyses, was : 



i 2 



Carbon. . 51.036 50.752 . 



Hydrogen. . 6.801 6-761 



Nitrogen. . 17-225 17-225 



Oxygen. 1 

 Sulphur. / 



100.000 100.000 



II. Compact horny matter. Hair was cut into small pieces, 

 well washed and digested in water, and finally boiled in alcohol 

 and in ether. Hair of the beard, thus treated, and dried at 

 212, left 0.72 per cent of ashes, when burned ; hair of a blond 

 colour from the head gave 0.3 per cent of ashes, the black hair 

 of a Mexican gave 2 per cent of ashes. The substance of nails 

 after similar preparation, gave 0.5 per cent of ashes, wool 2 per 

 cent. Horn sjave 0.7 per cent of ashes. Each of these substan- 

 ces was several times analysed, and the results from all were 



2 Y Y 



