Although of ordinary use in physic, the anatomy of tobacco is not yet discovered, nor hath Hoffmanus in his work of thirty years relieved us. That which comes fermented and dyed unto us affords no distinct account, in regard it is infected with a decoction or lixivium, which is diverse according to different places, and some ascend no higher than urine. Adulterations proceed further, adding euphorbium or pepper, and some do innocently temper it with gum of guaiacum.
The herb simply in itself and green and dried, is but flat, nor will it hold fire well upon ordinary exsiccation. Other plants are taken in the pipe, but they want quickness and hold not fire, only prick and draw........by their fulgio, which all smoke will do;and probably other herbs might be made quick and fire well, if prepared the same way, that is by fermentation, for in that alteration the body is opened, the fixed parts attenuated by the spirit, the oily parts diffused and the salt raised from the earthly bed wherein it naturally lieth obscure and heavy.
It containeth three eminent qualities, sudorific, narcotic, and purgative; from the subtle spirits and flying salt, sweat seems to proceed, for the ashes will not do it. The narcotic depends upon the humor impurus; for the vapopur thereof contains it, and the burnt part loseth it, as in opium. Poppy seeds dried are ineffectual, and the green heads work most powerfully; the same is observable in the mandichoca root, which being a strong poison, is harmless being dried. The purgative quality lieth in the middle principle, which goes not away from a gentle heat; for the water purgeth not, the smoke but very doubtfully, and seldom in clysters of the smoke of three or four pipefuls, nor in the salt thereof, neither incineration, but in the middle principles of the nitrous salt, and such parts as are to be extracted by tincture,infusion, or decoction, whose actives remain in the menstruum, and therefore that which is decocted, and after dried, grows faint in the purgative quality, if it returneth.
Of tobacco there is the male and female; the male the best. Yellow rhubarb is often taken for the true plant.
Tobacco may be made or cured without a caldo, and will ferment and grow brown long laid together, and hung up will grow brown. To advance the same the caldo may be added before the rolling up, for then it will have a quicker taste and sweeter smell.
The leaves first ripe make the best when they grow gummy and brittle; they must be often cleared of the sprouts that grow upon the same stem and the baschros left out.
To make the best tobacco, these to be taken, and of the male; and a good caldo used, and kept awhile, till time digest remaining crudities.
Source The Works of Sir Thomas Browne 3 Vols. Henry Bohn. London 1852