that quality which denotes a thing fruitful or prolific.

Nothing can produce fertility in either sex, but what promotes perfect health; nothing but good blood, spirits, and perfect animal functions, that is, high health, can beget perfect fecundity; and therefore, all means and medicines, all nostrums and specifics, to procure fertility, different from those which procure good blood and spirits, are arrant quackery. Dr Cheyne says, that water-drinking males are very rarely infertile; and that if any thing in nature can prevent infertility, and bring fine children, it is a milk and seed diet persevered in by both parents.

To increase the fertility of vegetables, says lord Bacon, we must not only increase the vigour of the earth and of the plant, but also preserve what would otherwise be lost; whence he infers, that there is much saved by setting, in comparison of sowing. It is reported, continues he, that if nitre be mixed with water to the thickness of honey, and after a vine is cut, the bud be anointed therewith, it will sprout within eight days. If the experiment be true, the cause may be in the opening of the bud, and contiguous parts, by the spirit of the nitre; for nitre is the life of vegetables.

How far this may be true, is not perhaps sufficiently shown, notwithstanding the experiments of Sir Kenelm Digby and M. Homberg. Consult Mr Evelyn's Sylva, the Philosophical Transactions, the French Memoirs, and Dr Stahl's Philosophical Principles of Chemistry; but a proper set of accurate experiments seems still wanting in this view.