3g2 PHILOSOPHICAL TRANSACTIONS. [aNNO IGQQ, 



magnitude, figure, and gravity, should ever constitute bodies so egregiousiy 

 unlike in ail those respects, as vegetables of different kinds are; nay, even as 

 the different [i.;rts of the same vegetable. That one should carry a resinous, 

 another a milky, a third a yellow, a fourth a red juice, in its veins : one afford 

 a fragrant, another an offensive smell : one be sweet to the taste, another bitter, 

 acid, austere, &c. that one should be nourishing, another poisonous, one purg- 

 ing, another astringent: in short, that there should be that vast difference in 

 them, as to their several constitutions, makes, properties, and effects, and yet 

 all arise from the very same sort of matter, would be very strange. 



The cataputia, in the glass e, received but very little increase, only 3^- grains 

 all the time it stood, though 2501 grains of water were spent upon it: the 

 reason of this may be, that the water was not a proper medium for it to grow 

 in ; and it is known that many plants will not thrive in it. Too much of 

 that liquor, in some plants, may probably hurry the terrestrial matter through 

 their vessels too fast for them to arrest it. Be that as it may, it is certain that 

 there are peculiar soils which suit particular plants: in England, cherries are 

 oberved to succeed best in Kent; apples in Herefordshire; saffron in Cam- 

 bridgeshire; wood in two or three of our Midland counties: and teasels in 

 Somersetshire, &c. But that soil which is once proper for the production of 

 some one sort of vegetable, does not always continue to be so ; for in time it 

 loses that property ; but sooner in some lands, and later in others. W wheat, 

 for example, be sown on a piece of land proper for that grain, the first crop 

 will succeed very well ; and perhaps the second, and the third, as long as the 

 ground is in heart, as it is termed. But in a few years it will produce no more, 

 if sowed with that grain. With some other grain indeed it may, as barley: 

 and after this has been sown so often, that the land can bring forth no more 

 of that kind, it may afterwards yield good oats ; and perhaps peas after them. 

 At length it will become barren ;. the vegetable matter that it at first abounded 

 in being extracted from it by those successive crops, is most of it borne off: 

 for each sort of grain extracts from it th it peculiar matter that is proper for its 

 own nourishment. After all this, that very tract of land may be brought to 

 produce another series of the same vegetables ; but not until it is supplied 

 with a new fund of matter, of like sort with that it at first contained ; which 

 supply is made several ways; cither by the ground's lying fallow some time, 

 until the rain has poured down a fresh stock upon it ; or by the tiller's care in 

 the manuring of it : and for further evidence that this sup])ly is in reality of like 

 sort, we need only reflect a while upon those manures that are found, by con- 

 stant experience, best to promote vegetation and the fruitfulness of the earth : 

 and these are chiefly either parts of vegetables, or of animals ; which indeed 



