Excerpt from A Practical Treatise on the Manufacture and Distribution of Coal GasThese were the chimeras vainly pursued during many ages by alchemists, and if we had not painful proof before our eyes that there are people who believe in the virtue of spirit-rapping and spirit-writing at the present day, we might be allowed to doubt the existence of alchemists in former times. But there are spirit-rappers now living, and beyond all doubt there were once alchemists, of whose peculiar operations it is recorded, that it is an art without an art, that begins with lying, is continued with labour, and ends with beggary, a description equally applicable to spirit-rapping.Nevertheless, alchemy has not been altogether useless in the development of science, for its absurd hopes and foolish attempts kept alive a spirit of inquiry regarding the metals, which really led to the discovery of the gases, and consequently to the ultimate expansion of chemical knowledge. Of the truth of this we may soon convince ourselves by a candid review of the discoveries which first proved that the gases had weight, and were material bodies, regarding which the ancients appear to have been wholly ignorant. This fact was discovered and demonstrated in the year 1630, by Jean Rey, a physician of Perigord, who noticed that both tin and lead increased in weight during alchemical calcination; and he attributed this augmentation of weight to the absorption of air, which he therefore supposed to be ponderable like other material bodies.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.

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