100 



HISTOLOGY OF HORN. 



hence it mast be injurious to the feet to be continually in 

 contact with manure which contains considerable quantities of 

 this alkali. According to Mulder the elements of the horse's 

 hoof are: — Carbon, 51-41; hydrogen, 6"96 ; nitrogen, 17'46 ; 

 oxygen, 19*94 ; sulphur, 4*23. 



Clement's analysis is as follows : — 



Lungwitz found by experiment that fresh, healthy horn from 

 the frog contained about 40 per cent, of water. In the case of 

 perioplic horn, however, this figure rises to 50. The excess of 

 water in the perioplic horn explains its greater softness and 

 flexibility. Fat is also present in small quantities in the horn, 

 being formed by fatty degeneration of the loose cells contained 

 in the horn tubes. In the soft horn structures of newly-born 

 animals the quantity of fat is sometimes so considerable that 

 little drops of it may be seen under the microscope. 



