of fever al Species of Poikn, 7j 



the capfules. As the vegetable focculum, wiiich confifls entirely of 



this kind of matter feparated from the folublc and fibrous part, has 



been, long confidered as the fame fubftance, though obtainable from 



different parts of vegetables, I extended the inquiry to tuberous 



roots, and obtained a further confirmation of the identity of pollen 



and fa^culum. A potatoe feems to be almoft nothing elfe but an 



affemblage of grains of fxculum, with their interftices occupied by 



the juice. If this root be boiled or baked until it becomes mealy, 



the juice will no longer be found; arid we might be at a lofs to 



know what was become of it, if the microfcope did not Ihow that it 



has entered into the grains of fasculum, which are thereby greatly 



diftended, as is, indeed, evident to the naked eye. The vital principle 



is thus deftroyed ; for thefe bloated grains will not move in fpirits, but 



give out a tinfture to it like other dead matter. By this means, and 



the lofs of folidity, they are prepared for more eafy dccompofition in 



the flomach. 



Starch is abfolutely infoluble in water. If water containing it be 

 made to boil, it becomes a jelly. I do not apprehend that a true 

 folution takes place even in this cafe. It appears that the fame 

 cffe6l is produced on the grains by the heat as by fpirit of wine. 

 They are difperfed into very minute particles; and the furface being 

 thus multiplied, a greater degree of attradlion takes place between 

 the ftarch and the water, and the former remains fufpended. 



It appears to me to be worthy of future inquiry, 



1. In what parts of vegetables in general the pollen or fa:culum 

 is to be found. 



2. In what refpeds that which is fecreted on the anther differs 

 from that which is contained in the root, feed, or fap. In the leaf, 

 petal, bulb, fibre of the root, or other parts already brought to per- 

 fedtion, I am inclined, from fome obfervation, to think it will not be 

 met with. 



Vol. Vr. L 3. Whether 



