ON THE FECULA OF GREEN PLANTS, 277 



In fact in the cheefe from gluten, as well as in that from Salts generated 

 animals, potato and fulphuric acid enable us to find that am- in cheefe » &c ' 

 monia, and that vinegar difcovered by Vauquelin. Is the 

 ammoniacal acetite then one of the ingredients which gives 

 the flavour to cheefe ? I only know that alcohol applied to 

 ftrong cheefe deprives it of all its tafle. An analyfis of that 

 fpecies might afford curious refults; but let us return to the 

 green fecula? ; examine them by the lights of modern che- 

 miftry, and endeavour more particularly to difcover whether 

 albumen actually exifts where Beccari and Rouelle found 

 gluten. 



Green Fecula, 



I. The fecula undergoes, by heat, a change capable alone The green fe- 

 of giving it a deciflve character as to its nature, I mean that cul * v ^P^ on " 

 concrefcibility which has fo few examples in vegetable pro- heat. 



duels ; that agglutination which comprefles the particles toge- 

 ther, and produces the appearance of a cheefy curd. Though 

 the fecula, before this change, paffed eafily through the 

 ftrainer, it can no longer do fo after having been heated ; a 

 peculiar hardening has deprived it of its tenuity ; but heat does 

 not coagulate the fibrous tiffue ; in this refpect the fecula does 

 not refemble the broken ftraw of green plants. 



II. The fecula, feparated from the juice by filtration, ac- Elaftic and 

 quires an elaftic and horny confidence by drying. It is fof- ^ orn y when 

 tened with difficulty in heated water, but will not become foft 



even at the end of a month ; notwithstanding it is moiftened it 

 ftill retains its horny flate. When bended it will return to its 

 fhape, and cannot by any means be crumbled : thefe quali- 

 ties alfo are not found in the dry woody pulp. 



The feculns of green and white cabbages, creffes, hemlock, More concrefci. 

 &c. do not lofe the property of coagulating by heat from that^ e e than white 

 caufe. Into water heated to between 50 and 60 degrees, 

 plunge two matraffes of equal fize, one containing diluted 

 fecula, and the other with the water and white of an egg; 

 the fecula will harden and be collected in flocks, fuch as are 

 formed in a juice which is clarified by heat; but at this tem- 

 perature the albumen will not even lofe its tranfparency. 



III. The green fecula is very nearly in equipoife with wa- 

 ter, for that of plants which are not acid, frequently requires 

 a week to precipitate. 



Put 



