On the Fecula of Green Plants. S5 



Consequences. 



White fecula deposited spontaneously, or by alcohol, by 

 acids, salts, &c. is insoluble in water: on the other hand, 

 acids which precipitate fecula do not alter solution of albu- 

 men. 



No salt is capable of separating albumen from water; but 

 the contrary is the case with fecula : it adheres so weakly to 

 water that there is not one of them which does not separate 

 it, and consequently obhgc it to be deposited. 



White of egg dried and leii to soften returns to the same 

 volume, opacity and v .,iteness, as baked albumen. The 

 case wieh white feculse is different : they acquire a strong 

 brown colour. The greater part even bc^conie entirely black 

 in drying, as those of cresses, cabbage, th^solanum Llcoper- 

 sicum, &c.; and if they become soft in water they never 

 assume the appearances observed in white of egg. In a 

 word, this fecula is nothing else than a part of tiie gluten 

 which forms the base of green fecula. Thus, for example, 

 if the fecula of white cabbage, separated by the filter, be 

 compared with that which the juice of it gives by heat, botli 

 deprived of colouring matter, the smallest difference will 

 not be found. But it is the white fecula in particular which 

 dissolves easiest, because it is not, like green fecula, in a state 

 of combination, which opposes its solution. All plants 

 contain a portion of giuten, which not having been vivilicd 

 by the light remains colourless. 



Cabbage, succory, escarolle, and plants blanched by the 

 art of the gardener, give also white fecula, but in much 

 less quantity than when they remain green. The stem of 

 the cabbage and that of hemlock give pale fecula in com- 

 parison of that produced by their leaves. But vegetables 

 in general have not always need of being highly coloured 

 externally- to announce their abundance in gluten. The 

 small joubarbe gives abundance of well coloured fecula, 

 which is particularly rich in wax, as will be seen here- 

 after. 



VIII, But it may be said. As albumen is the only product 

 which has been remarked to possess the property of coagu- 

 lating by heat, it seems natural thence to conclude. Sec. 

 But inilk of almonds curdles also by heat, by alcohol, acids, 

 &c. This is a fact well known in apothecaries' shops; and 

 yet it has never been concluded from this appearance that 

 emulsions contain white of egg ; because, even if characters 

 of aniuiulization were obscr\cd in the principles of cmul- 



tiion. 



