46 VEGETABLE FIBRINE 



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leaves a greyish white substance, well known to 

 druggists as the deposit from vegetable juices. This 

 is one of the nitrogenised compounds which serves 

 for the nutrition of animals, and has been named 

 vegetable fihrine. The juice of grapes is especially 

 rich in this constituent, but it is most abundant in 

 the seeds of wheat, and of the cerealia generally. 

 It may be obtained from wheat flour by a mechan- 

 ical operation, and in a state of tolerable purity; 

 it is then called gluten, but the glutinous ^^roperty 

 belongs, not to vegetable fibrine, but to a foreign 

 substance, present in small quantity, which is not 

 found in the other cerealia. 



The method by which it is obtained sufficiently 

 proves that it is insoluble in water ; although we 

 cannot doubt that it was originally dissolved in the 

 vegetable juice, from which it afterwards separated, 

 exactly as fibrine does from blood. 



The second nitrogenised comjoound remains dis- 

 solved in the juice after the sej^aration of the fibrine. 

 It does not separate from the juice at the ordinary 

 temperature, but is instantly coagulated when the 

 liquid containing it is heated to the boiling point. 



When the clarified juice of nutritious vegetables, 

 such as cauliflower, asparagus, mangel wurzel, or 

 turnips, is made to boil, a coagulum is formed, which 

 it is absolutely impossible to distinguish from the 

 substance which separates as a coagulum, when 

 the serum of blood or the white of an ^gg, di- 

 luted with water, are heated to the boiling point. 



