258 PROFESSOR LIEBIG ON THE AZOTIZED 
although not in the same state; that the juices of plants contain 
albumen; that wheaten flour, and corn in general, contain the 
ingredients of the muscular fibres; that beans, peas, and len- 
tils contain the same substances that are found in the milk of 
animals. They are nourished by the flesh, blood, and cheese 
produced by the plants, whilst their own flesh and blood serve 
as nourishment to carnivorous animals. The resemblance of the 
azotized principles of vegetables and the ingredients of the 
blood is not confined to the chemical composition; it is not 
merely a similarity in the numbers of atoms, but the behaviour 
with reagents is the same in vegetable and animal albumen and 
casein. 
Vegetable albumen obtained from the juices of plants by boil- 
ing, and washed from fatty and colouring matter by alcohol and 
zther, cannot possibly be distinguished from animal albumen, 
precipitated from its aqueous solution by boiling; the external 
appearance of the former is the same as that of the latter, and 
also its behaviour with alkalies, acids, the infusion of gall-nuts, 
corrosive sublimate, creosote, &c. The same may be said of 
vegetable casein: this substance appears to occur very frequently 
in vegetable substances, and is found in considerable quantities 
in all oily seeds. An emulsion of these seeds is very like the 
milk of animals, but contains a much larger proportion of albu- 
men. Vegetable milk contains a fat corresponding to butter, 
also sugar, casein, and albumen; these latter two are evidently 
in union with alkalies; when heated, the albumen coagulates, 
and rises with the oil to the surface of the liquid; when sepa- 
rated from the coagulum it becomes sour in twenty-four hours, 
and a pure precipitate of caseum is obtained, leaving lactic acid 
in the solution. A solution of pure crystallized cane sugar left 
with vegetable casein for several days in a gentle warmth, was 
converted entirely into acetic acid, lactic acid, and a body resem- 
bling gum arabic, just as when left with common animal cheese. 
A considerable quantity of sulphuret of potassium is obtained 
from the casein of sweet almonds and leguminous plants, warmed 
for a length of time in caustic potash. Acids precipitate protein 
from this solution, and cause the escape of sulphuretted hydrogen. 
The body named vegetable fibrin by me, is the same as that 
called by Berzelius vegetable albumen of the cereals ; but if, as 
is proved by the analyses, these names refer only to different modi- 
fications of the same body, the name of albumen cannot be given 
