126 On the Fecula of Green Plants. 



I know only that alcohol applied to pungent cheese de- 

 prives it of all its savour. An analysis directed to this point 

 might give us curious results : but let us return to the green 

 feculae; let us try them by the test of modern chemistry; 

 and, in particular, let us endeavour to discover whether al- 

 bumen really exists wliere Beccari and Rouello found gluten. 

 Green Fee id a. 



I. Fecula exposed to heat experiences a change capable 

 of furnishing it alone with a decisive character in regard to 

 its nature. I allude to that concrescibility of which there 

 are few examples among vegetable products ; that aggluti- 

 nation which attaches its moleculae to each other, and gives 

 them the appearance of caseous curd. If fecula before ihis 

 change passes easily through the cloth, it can no longer do 

 so when boiled ; a peculiar crispation has then deprived it 

 of its tenuity ; but heat does not coagulate the fibrous tissue. 

 The fecula, therefore, in this point of view, cannot be com- 

 pared to the torn straw of green plants. 



II. Fecula separated flom juices by filtration assumes in 

 drying a corneous and elastic consistence. It becomes soft 

 with difficulty in boiling water, but it does not acquire soft- 

 ness even at the end of a mouth : notwithstanding its hu- 

 mectation it always retains its corneous nature. It recovers 

 its former state if bent, but absolutely refuses to crumble :. 

 all these are qualities which are not observed in dried lig- 

 neous pulp. 



The feculae of green and white cabbages, cresses, hem- 

 lock, Sec. do not by these means lose their property of co- 

 agulating by heat. In warm water between 145 and 165 de- 

 grees, if two equal matrasses be immersed, one with diluted 

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

 the fecula becomes crisp and is collected in flakes, such as 

 those seen in any juice exposed to heat in order to be cla- 

 rified ; but at that temperature albumen does not even lose 

 its transparency. 



III. Green fecula is nearly of the same weight as water; 

 for that of plants which are not acid employs more than 

 eight days to deposit itself. 



If fecula washed and diluted be poured into three jars, 

 and if a little alcohol be added to the first, a few drops of 

 acid to the second ; and if the third be placed between the 

 other two for the sake of comparison, the fecula in the 

 two former will be completely deposited in less than half 

 an hour, while that in the third scarcely begins to fall. Al- 

 cohol and acids then have the power of coagulating fecula, 

 but they do not exercise the same action on woody remains, 



IV. A 



