Penfyhania, Journey to Wilmington. 153 



grows eight or ten feet high, but in a hard 

 and poor ground, it will feldom come up 

 to fix inches. This Datura, together with 

 the Phytolacca, or American Nightfiade, 

 grow here in thofe places near the gardens, 



houfes, 



analyfis of plants, fhews that they confift of water, earth, 

 acid, alkali, oil, and an inflammable principle, independent 

 of the laft fubftance, and called by a late German chemift the 

 cauftic : thefe fubftances muft enter yearly the new plants, 

 and make their fubftance, and are as it were regenerated in 

 thefe new plants, after being fet at liberty from the ftrutture 

 of the laft year's plants by putrefa&ion, or by fire. Mould 

 chemically examined, has the fame analogous parts. Acid 

 and cauftic are plentifully contained in the common air, and 

 may alfo eafily be reftored to the mould, and thus circulate 

 through a new fyftem of plants. Water comes likewife from 

 rain and fnow, out of our atmofphere : alkaline and oily 

 particles, or a kind of /cap, are the only things wanting, 

 which when added with the former to any fubtle earth, will 

 make a good mould, and thefe are produced by putrefaction 

 or fire, from vegetable and animal fubftances, and are the 

 great promoters of vegetation. 



But the great queftion is, from whence thefe various 

 fubftances neceflary for vegetation originally came? To 

 believe they are produced from putrified vegetables is 

 begging the queftion, and making a tiradus njitio/us 

 in the argument. There is therefore no evafion ; they 

 were certainly produced by the great Creator of the uni- 

 verfe, and endowed with fuch qualities, as make them 

 capable of producing in various mixtures new bodies ; and 

 when they are introduced by moifture, into the firft ftamina 

 of a plant, or a feed, they expand thefe ftamina, and conftitute 

 a new being, capable of affording food to the animal creati- 

 on. It is evident, Mr. Kalm hinted at the above-mentioned 

 opinion of the increafe of mould, and this gave me an oppor- 

 tunity of confirming his argument, and of ftating fairly the 

 great queftion on which agriculture, the moft neceflary branch 

 of human arts depends. F. 



