On Onions. Jd 21 
For instance the daisy, which grows wild in great pro- 
fusion inthe 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 
