313 On the Food of Plants. 
1792 and 1793 I put various seeds to vegetate-in different 
airs; in atmospheric air, in vital air, and in azote. The 
general result was, that neither wheat, oats, nor barley, ve- 
getated in azote; but in vital air vegetation was nabioraly 
rapid. 
July 12, 1796, I placed eleven cabbage plants in pots, al] 
healthy plants, and weighing each a quarter of an ounce 
apothecaries’ weight. The pots stood in pans with water, 
and remained mm them till June 12, 1797, when the plants 
were taken out of the pots and weighed again. 
OF these pots four had quartz eel washed clean, and 
rendered perfectly free from mixture of either argil or cal 
careous earth. d 
Ne. 1. had nothing bur this sand: the plant lived, but 
did not increase in bulk; when examined, the radical fibres 
were found numerous and extended, but very small; and, 
when the plant was weighed in January 1797, it had not in- 
creased in weight. 
~ No. 9. had the same kind of sand and woollen rags: the 
roots shot vigorously, the plant cabbaged, and in January 
1797 weighed two ounces. 
No. 3. had the same kind of sand, with seeee 1-4th part 
charcoal in powder: the roots were less vigorous than the 
former, and in January 1797 the plant weighed 3-4ths of an 
ounce. 
No. 4. had this sand with about 1-20th lime. The plant 
did not increase, yet lived, and in January 1797 weighed 
only 3 dwts., having lost 2-5ths of its original weight. 
No. 5. had brickmaker’s clay alone: the plant lived, 
looked fresh, but in January 1797 weighed only half an 
ounce. 
No. 6. had brickmaker’s clay, with an equal proportion 
of the quartz sand. This plant, like the former, livedg 
looked fresh, and in January 1797 weighed half an ounce. 
No. 7. had brickmaker’s clay, with about 1-4th part 
charcoal in powder. In January 1797 the plant weighed 
half an ounce. : 
No. 8. had brickmaker’s clay and woollen rags. This plant 
eabbaged well, and in January 1797 weighed four ounces. 
No. 
