ON THE KECUL1 OF GREEN PLANTS.- 21 



7th. Cryftallized carbonate of potato, magnefia, fea-falt, and with com- 

 n „ ^i n ,i • i~ pound falts. 



muriate of potato, fal-ammonia, faltpetre, &c. thrown into r 



a filtered juice, caufe the feeula, which by its nature is but 



little foluble, to precipitate in proportion as they diffolve. 



The water of the albumen is not difturbed by any of thefe falts. 



Confluences. 



The white feeula depofited fpontaneoufly, or by alcohol, Feeula infoluble 

 • i r i .-» • • r i i i • t,, it ■ ,l in water; albu- 



acids, falts, &c. is infoluble in water. The albumen is the re- men fo]uble# 



verfe : the acids which precipitate the feeula, do not alter the 



folution of albumen. 



No fait is capable of depriving the albumen of water ; but 

 with the feeula it is different; its affinity for water is fo weak 

 that there is none which does not deftroy it; and, consequently 

 precipitate it. 



The white of egg dried and afterwards foftened is reftored, Other ftriking 

 in bulk, in opacity, in whitenefs to boiled albumen. Not fo differences, 

 the white feeula ; it becomes of a deep brown. Nay the 

 greateft number are entirely blackened in drying, fuch asthofe 

 of cabbage, creffes, folanum lico perficum , &c. and if they are 

 foftened in water, they will never affume the appearances 

 which are known in white of egg. In toort, this feeula is 

 nothing but a part of the gluten which forms the bafis of the 

 green feeula. If, for example, the feeula of white cabbage, Green and white 

 feparated by the filtre, be compared with that which is ob- fecu!a * 

 tained from its juice by heal, and both he deprived of their 

 colouring parts, the final left difference will not be difcovered. 

 But, above all, the white feeula is the moft eahly difiblved, 

 becaufe it is not, like that which is green, in a ftate of com- 

 bination which oppofes it. All plants contain a portion of 

 gluten, which, not having been vivified by the light, remains 

 without colour. 



The cabbage, the endive, the (efcarolle) and the plants 

 blanched by the art of the gardener, alfo yield white feeula, 

 but in much lefs quantity than when they are permitted to re- 

 main green. The ftalk of the cabbage and that of hemlock 

 afford pale feeula in comparifon with that obtained from their' 

 leaves. But in general it is not neceflary that vegetables fliould 

 fliow much colour outwardly to indicate their pofTeffing much 



gluten. 



