£0 ON THE FECULA OF GREEN PLANTS. 



inftant thejuice will be clouded with cheefe-like flocks which 

 fall to the bottom ; but at this temperature, the albumen does 

 not experience the flighted change. 



Fee ula, though 2d. Place on a furnace two matrafles, the one with juice 



fails by heat! m i xe d with twenty parts of water, and the other with albu* 

 men. The fecula, however diluted it may be, will never- 

 thelefs be entirely feparated by the heat ; thus clearly proving 

 its infolubility. With refpect to the water of the albumen, as 

 it heats, it opalifes, without loiing its tranfparency ; it boils, 

 and becomes contracted, but does not depofit flocks, or any 

 thing refembling fecula. And, if at laft the evaporation be 

 com pleated in an open veflel, it ends by leaving only a coat 

 of white egg. Darcet has already (hewed that albumen dif- 

 perfed in a great quantity of waiter, is no longer feparable by 

 heat. Albumen is a foluble mucilage, fecula is not; and the 

 temperature which coagulates the latter produces no change 

 on the ftateof thefirft. 



Fecula conti- 3d. The wa ter of albumen remains feveral days unaltered ; 



nua y epara . ^ e j u j ce f plants, on the contrary, is in a continual ftate of 

 change which never ceafes to difturb its tranfparency. Filter 

 the juice, it becomes turbid; repeat the filtering, it again be- 

 comes clouded ; in fliort it continually depofits white fecula. 



Albumen a&s 4th. Albumen changes the juice of violets green, and re- 



on tefts like an ft ores re ddened turnlole to blue. 



alkali : fecula , . „ , _ . k . . . r , r 



not. J he white tecula, walned, does not produce either or thele 



changes. And how fhould it? The juices of cabbage, hem- 

 lock and many others redden turnfole. Betides the property 

 of changing it to green is not polTefled by the albumen itfelf : 

 it is known to be owing to a mixture of alcali. 

 .They differ m 5th. Alcohol feparates light, tranfparent, glary flocks from 



alcohol- WU *^ e vvater °f albumen, which retain, on the filtre, the ap- 

 pearance of boiled white of eg£. The juice of plants only 

 yields to alcohol a whitifli opake powder, which quickly falls 

 to the bottom of the veflel. 



withacloV 6i ^' All the acids, hidro-fulphurated water, and ammonia 



precipitate the fecula diflblved in the juices ; but thefe re-agents 

 operate no change on the water of albumen. 



*»th ox.mur. The oxigenated muriatic acid precipitates and oxidates" the 



■*** » white fecula ; the fame acid firft oxidates and then precipitates 



the albumen. 



7th, Cryflallized 



