Dr. Nehemiah Grew.
Born, 1628; died, 1711.
(From an engraving by R. White, from life.)
Dr. Grew was for many years secretary of the Royal Society and editor of the Philosophical Transactions. He was one of the pioneers of the science of structural botany and author of The Anatomy of Plants.
It was Dr. Grew who first extracted the salt from the Epsom water, and his treatise deals principally with that. He describes the effect of adding all sorts of chemicals, oil of vitriol, salt of tartar, nitre, galls, syrup of violets, and other substances to the solution; explains how it differs from the sal mirabilis (sulphate of soda); and writes of its delicate bitter taste as if he were commenting on a new wine. It most resembles the crystals of silver, he says, in the similitude of taste.
As to the medicinal value of this salt Dr. Grew says it is free from the malignant quality of most cathartics, never violently agitates the humours, nor causes sickness, faintings, or pains in the bowels. He recommends it for digestive disorders, heartburn, loss of appetite, and colic; in hypochondriacal distemper, in stone, diabetes, jaundice, vertigo, and (to quote the English translation) “in wandering gout, vulgarly but erroneously called the rheumatism.” It will exterminate worms in children in doses of 1½ to 2 drachms, if given after 1, 2, or 3 grains of mercurius dulcis, according to age. Epsom salts were not to be given in dropsy, intermittent fevers, chlorosis, blood-spitting, to paralytics, or to women with child.
“I generally prescribe,” writes the doctor, “one, two, or three pints of water, aromatised with a little mace, to which I add ½ oz. or 1 oz., or a greater dose of the salt.” He gives a specimen prescription which orders 1 oz. or 10 drachms of the salt in 2 quarts of spring water, with 1 drachm of mace. This dose (2 quarts, remember) was to be taken in the morning in the course of two hours, generally warm, and taking a little exercise meanwhile. This was what was called an apozem. You might add to the apozem, if thought desirable, 3 drachms of senna and 1½ oz. or 2 oz. of flaky manna.
Mr. Francis Moult, Chymist, at the sign of the Glauber’s Head, Watling Street, London, translated Dr. Grew’s treatise into English, and gave a copy to buyers of the Bitter Purging Salts. Probably he was the “furnace philosopher” referred to by Quincy (see below), though it is difficult to see what there was to object to in his action.
George and Francis Moult (the latter was, no doubt, the chymist who kept the shop in Watling Street) in about the year 1700 found a more abundant supply of the popular salt in a spring at Shooter’s Hill, where it is recorded they boiled down as much as 200 barrels of the water in a week, obtaining some 2 cwt. of salt from these. Some time after, a Dr. Hoy discovered a new method of producing an artificial salt which corresponded in all respects with the cathartic salts obtained from Epsom water, and which by reason of the price soon drove the latter out of the market, and caused the Shooter’s Hill works to be closed. It was known that Hoy’s salt was made from sea water, and at first it was alleged to be the sal mirabilis of Glauber, sulphate of soda. But this was disproved, and experiments were carried on at the salt works belonging to Lady Carrington at Portsmouth, and later at Lymington, where the manufacture settled for many years, the source being the residue after salt had been made, called the bittern—salts of magnesium, in fact. This was the principal source of supply, though it was made in many places and under various patents until in 1816 Dr. Henry, of Manchester, took out a patent for the production of sulphate of magnesia from dolomite.