50

A DISCOURSE

corn-fed birds, so eminently effectual before the soil of horses and otherbeasts, in which it lefs abounds, as having lefs virtue to attract it

It is salt that gives such vigour to places sprinkled with urine, soot»ashes, &c. which have them not diluted; and to bones, flesh, horn, hair^feathers, blood, and the rest of those animal excrements : And whencethose seminal mafses should proceed after calcination of the Earth , whenit comes to be exposed again, is hard to divine ; whence, I say, they shouldderive their life and energy, without being destroyed by so powerful anagent as fire, unlefs they lurk in some vegetant and indifsoluble salts, (vo-latile, fixed, or nitrous Earth, ) from whence they (Phceriix-like) emerge,though I do not say without any other specific rudiment: But it is strange,what, as I remember Dr. Morison affirms of the Erysimum, or lino, so sel-dom seen to grow spontaneously in England before the late prodigiousconflagration of this City, when there appeared more of it amongst the

ruins, than was known to grow in all Europe besides : it being a curious

exotic, to be found most about Naples in the time ofFabius Columna, andbut rarely elsewhere f .

It is salt which resuscitates the dead and mortified Earth , when, languish-ing and spent by indulgence to her verdant offspring, her viguor seems tobe quite exhausted, as appears by the rains and showers which gentlymelt into her bosom what we apply to it, and for which cause all ourcomposts are so studiously made of substances which most ingender or.attract it..

• The richnefs of poultry and pigeon dung appears rather to arise from its being over-charged with oil and mucilage, than any thing saline. For further information upon this,subject, consult the-note upon the 27th page of the 1st vol. of the Silva-.

t This is the Sisymbrium (Irio) folds runcinath dentath nudis, caule lavi, filijuis crectis. Lin,.Two years ago a crop of wild mustard (Erysimum vulgare. Bauh.) was reaped from thebanks raised at Hull to form a dock for the reception of shipping; and it is generally ob 1served that a spontaneous crop of thiss vegetable makes its appearance, for two succefsiveyears, upon the banks of all large drains made in Holdernefs. Similar appearances havebeen observed in the isle of Axholme and other low countries. This phenomenon provesthat seeds, when kept from air, may retain their vegetative power many years beyond theterm seemingly allotted them.