54 INTRODUCTION. 



The other elements not so extensively diffused, we will 

 briefly notice. They are as follows : 



Pepsin was discovered by Schwann in the gastric juice, 

 the parietes of the follicles and glands of the stomach, and 

 may be obtained by macerating the stomach of an animal. 

 "With an acid it readily dissolves albumen and fibrin 

 resembles very much albumen and is considered the ac- 

 tive agent in digestion, the prime element in converting 

 the food into chyme. 



Chemical Analysis makes Pepsin consist of Oxygen 10, 

 Hydrogen 32, Nitrogen 8, Carbon 48. 



Globulin exists in the envelopes of the blood corpuscles, 

 and resembles albumen. Simon regards it as casein united 

 with hgematin. 



Spermatin is found in the seminal fluid, and looked upon 

 as probably only fibrin. 



Mucus is furnished by the mucous glands. It is insoluble 

 in water, transparent when evaporated to dryness, is soluble 

 in acids, does not coagulate by heat, is precipitated by 

 tannin, and is always found united with the cast-off epithe- 

 lium and pus. 



Lachrymal matter. This is found in the tears after evap- 

 oration, and is regarded as insoluble mucus. 



Keratin is so named from being found in the nails, hair, 

 and cuticle, though its character is not yet fully determined. 



EXTRACTIVE ELEMENTS. 



When protein and the salts are removed from animal 

 matter, what is left is called Extractive matter. 



This is found pretty generally diffused through the body, 

 but most abundant in muscle. 



The dried extract of flesh, if treated with water, diluted 

 alcohol, or pure alcohol, forms either a water extract, spirit 

 extract, or alcoholic extract. 



The spirit extract is termed ozmasome, (from o<y^, smell, 

 and ^ajuof, soup,) because it gives the flavor to soups. 



