10 CLASSICS OF MODERN SCIENCE 

 to remain in the ground for forty or fifty years, and to be transmitted 

 to their heirs as a sort of artificial mine), and the hke. The con- 

 densations which take place in nature, by means of cold, should also 

 be investigated, that by learning their causes, they may be introduced 

 into the arts ; such as are observed in the exudation of marble and 

 stones, in the dew upon the panes of glass in a room towards morning 

 after a frosty night, in the formation and the gathering of vapors 

 under the earth into water, whence spring fountains, and the like. 

 Besides the substances which are cold to the touch, there are 

 others which have also the effect of cold, and condense ; they appear, 

 however, to act only upon the bodies of animals, and scarcely any 

 further. Of these we have many instances, in medicines and plasters, 

 f Some condense the flesh and tangible parts, such as astringent and 

 ^ inspissating medicines, others the spirits, such as soporifics. There 

 are two modes of condensing the spirits, by soporifics or provocatives 

 to sleep; the one by calming the motion, the other by expelling the 

 spirit. The violet, dried roses, lettuces, and other benign or mild 

 remedies, by their friendly and gently cooling vapors, invite the 

 spirits to unite, and restrain their violent and perturbed motion. 

 Rosewater, for instance, applied to the nostrils in fainting fits, causes 

 the resolved and relaxed spirits to recover themselves, and, as it 

 were, cherishes them. But opiates, and the like, banish the spirits 

 by their malignant and hostile quality. If they be applied, therefore, 

 externally, the spirits immediately quit the part and no longer readily 

 flow into it; but if they be taken internally, their vapor, mounting 

 to the head, expels, in all directions, the spirits contained in the 

 ventricles of the brain, and since these spirits retreat, but cannot 

 escape, they consequently meet and are condensed, and are some- 

 times completely extinguished and suffocated; although the same 

 opiates, when taken in moderation, by a secondary accident (the 

 condensation which succeeds their union), strengthen the spirits, 

 render them more robust, and check their useless and inflammatory 

 motion, by which means they contribute not a little to the cure of 

 diseases, and the prolongation of life. 

 . The preparations of bodies, also, for the reception of cold should 

 not be omitted, such as that water a little warmed is more easily 

 frozen than that which is quite cold, and the like. 



Moreover, since nature supplies cold so sparingly, we must act like 



