VOL. XXI.] PHILOSOPHICAL TRANSACTIONS. 38^ 



to US, according to the nature of the plants from whence they arise : and since 

 these owe their origin to the water that ascends out of the earth through the 

 bodies of plants, we cannot be at a loss why they are more numerous in the 

 air, and why we find a greater quantity of odours exhaling from vegetables in 

 warm, humid seasons, than in ethers. 



3. A great part of the terrestrial matter that is mixed with the water, ascends 

 up into the plant, as well as the water itself: for there was much more terrestrial 

 matter at the end of the experiment in the water of the glasses f and g, that 

 had no plants in them, than in those that had: the garden-mould dissolved in 

 the glasses k and l was considerably diminished, and carried off; nay the ter- 

 restrial and vegetable matter was borne up in the tubes filled with sand, cotton, 

 &c. in such a quantity as to be evident even to sense. 



Our shores, and parts within the verge of the sea, will present us with a large 

 scene of plants that, along with the vegetable, take up into them mere mineral 

 matter also in great abundance: such are the seapurslains, the several sorts of 

 algas, of samphires, and other marine plants, which contain common sea- salt, 

 which is all the same with the tbssil, in such plenty as not only to be plainly 

 distinguished on the palate, but is extracted from them in considerable quanti- 

 ties. How apt this vegetable matter, being so very fine and light, is to attend 

 water in all its motions, and follow it into each of its recesses, is manifest from 

 the instances above alledged, and many others. Percolate it with all the care 

 imaginable ; filter it with ever so many filtrations, yet some terrestrial matter 

 will remain : the fluid will indeed be thinner every time, and more disengaged 

 of the said matter ; but never wholly free and clear. I have filtered water 

 through several sheets of thick paper, and after that through very close fine 

 cloth, 12 times doubled; nay, I have done this over and over; and still a con- 

 siderable quantity of this matter discovered itself in the water after all. Now if 

 it thus pass interstices that are so very small and fine along with the water, it is 

 the less strange it should attend it in its passage through the ducts and vessels 

 of plants. It is true, filtering and distilling of water intercepts and makes it 

 quit some of the earthy matter it was impregnated with ; but then that which 

 continues in the water after this, is fine and light, and such consequently as is 

 in a peculiar manner fit for the growth and nourishment of vegetables. And 

 this is the case of rain water : the quantity of terrestrial matter it carries up 

 into the atmosphere, is not great ; but what it does, is chiefly of that light kind 

 of vegetable matter, and that too perfectly dissolved, and reduced to single cor- 

 puscles, all fit to enter the tubules and vessels of plants: on which account it is 

 that this water is so very fertile and prolific. But a great deal of the mineral 

 matter not only gross and ponderous, but scabrous and inflexible, and so not 



