Glauber was twenty-one at that time, and knew nothing of chemistry. Later he analysed the water and got from it, after evaporation, long crystals, which, he says, a superficial observer might confuse with saltpetre; but he soon satisfied himself that it was something quite different. Subsequently he obtained an identical salt from the residue in his retort after distilling marine salt and vitriol to obtain spirit of salt. As already stated, he believed he had produced the “sal enixon” of Paracelsus. But in memory of the benefit he had himself experienced from its use he gave it the title of “sal mirabile.”
In the seventeenth and eighteenth centuries the sign of “Glauber’s Head” appears to have been used in this country by some chemical manufacturers. The picture annexed is from one of these signs which was used more than a hundred years ago by Slinger and Son, of York, and is now in the possession of Messrs. Raimes and Co., of that city, who have kindly given me a photograph of it. It is a wooden bust which was once gilded, and presumably presents the traditional likeness of the famous German chemist.
This distillation of sulphuric acid with sea-salt, which yielded spirit of salt, or as it is now called hydrochloric acid, was probably Glauber’s principal contribution to the development of chemistry. He observed the gas given off from the salt, and it is a wonder that with his acuteness he did not isolate and describe the element chlorine. He called it the spirit of rectified salt, and described it as a spirit of the colour of fire, which passed into the receiver, and which would dissolve metals and most minerals. He noted that if digested with dephlegmated (concentrated) spirit of wine his spirit of salt formed a layer of oily substance, which was the oil of wine, “an excellent cordial and very agreeable.” He distilled ammonia from bones, and showed how to make sal ammoniac by the addition of sea salt. His sulphate of ammonia, now so largely used as a fertiliser and in the production of other ammonia salts, was known for a long time as “Sal ammoniacum secretum Glauberi.” He made sulphate of copper, and his investigation of the acetum lignorum, now called pyroligneous acid, though he did not claim to have discovered this substance, was of the greatest value. He produced artificial gems, made chlorides of arsenic and zinc, and added considerably to the chemistry of wine and spirit-making.
Glauber worked at many subjects for manufacturers, and sold his secrets in many cases. His enemies asserted that he sold the same secret several times, and that he not unfrequently sold secrets which would not work. It is impossible now to test the truth of these accusations. Probably some of the allegations made against him were due to the fact that those who bought his processes were not as skilful as he was. One secret which he claimed to have discovered he would neither sell nor publish. It was that of the Alkahest, or universal solvent. To make this known might, he feared, “encourage the luxury, pride, and godlessness of poor humanity.”
Oliver Cromwell wrote in an old volume of Glauber’s Alchemy: “This Glauber is an errant knave. I doe bethinke me he speaketh of wonders which cannot be accomplished; but it is lawful for man too the endeavour.”
Glauber complained that he was not appreciated, which was probably true. “I grieve over the ignorance of my contemporaries,” he wrote, “and the ingratitude of men. Men are always envious, wicked, ungrateful. For myself, faithful to the maxim, Ora et Labora, I fulfil my career, do what I can, and await my reward.” Elsewhere he writes, “If I have not done all the good in the world that I should have desired, it has been the perversity of men that has hindered me.” His employees, he says, were unfaithful. Having learned his processes, they became inflated with pride, and left him. Apparently there was a good business to be done in chemical secrets at that time. But Glauber did not give away all he knew, and he found it best to do all his important work himself. “I have learnt by expensive experience,” he wrote, “the truth of the proverb, 'Wer seine Sachen will gethan haben recht, Muss selbsten seyn Herr und Knecht.’”
Although all Glauber’s books appeared with Latin titles they were written in German.