On Onions. 21 



For instance the daisy, which grows wild in great pro- 

 fusion in the pasture grounds in Scotland, cannot be 

 kept alive here but with the greatest care. The oats 

 of this country where they ripen in a few days, pro- 

 duce a poor, thin,, shrivelly grain, compared with those 

 of the North of Europe where they require as many 

 weeks to ripen as days here. The onion likewise is a 

 plant whose small fibrous roots reach but a short way 

 into the soil, and of course is soon dried up ; besides 

 it is a plant which requires a great quantity of nourish- 

 ment, and for that reason must not only have a very 

 rich soil, but a constant supply of moisture to bring it 

 to full maturity. 



The potatoes of this country likewise when the dry 

 weather sets in, generally assume a premature ripeness, 

 and if showers afterwards occur, the bulbs being al- 

 ready hardened, do not swell any more, but take what 

 is called the second growth. This I conceive to be 

 chiefly owing to an error in the prevailing mode of cul- 

 ture, which I think I have completely obviated by a 

 different mode I have practised, and which I shall 

 make the subject of a future memoir. 



Here I would beg leave to observe farther, that most 

 of the land in the neighbourhood of Philadelphia being 

 alluvial or made ground, it acts like a filter for draw- 

 ing off the moisture which should nourish plants ; be- 

 sides there exists a stratum of sand at different degrees 

 of depth, which must attract the water, and assist the 

 filtration ; (this circumstance together with the burning 

 hot sun which prevails here in the latter part of sum- 

 mer completely deprives many plants of moisture, ex- 

 cept such as have long tap roots, or strong fangs which 



