soluble in water. Examining the liquid which was left, he observed glycerine.
In a memoir relative to a new method of preserving vinegar (1782), Scheele showed that further change could be prevented by bringing the vinegar to the boiling-point. Scheele was the first to examine the substances which give an acid taste to fruits and plants. To this order belongs his examination of the "salt of sorrel." He also, in one of bis earlier scientific labors, isolated tartaric acid, and introduced the method by which numerous other organic acids have since been separated. In 1784 he discovered citric acid in the lemon, gooseberry, and other fruits, and malic acid in the gooseberry and in fruits generally; and shortly before his death he produced gallic acid, or "salt of gall-nuts," from which he distilled pyrogallic acid, which has been found useful in photography. He first found benzoic acid, saccharic acid, and mucic acid. Examining what was called rhubarb-earth, in 1784, he found it to be composed of oxalate of lime, and from this proceeded to show that that substance is generally present in roots and bark.
In animal chemistry, he examined the concretions of urinary calculus, discovered uric acid, observed its connection with intermittent fevers, and prepared alloxane and cyanuric acid. In 1780 he investigated the phenomena of the curdling of milk, and speculated as to its cause, and in this research discovered lactic acid.
Scheele's nomination as member of the Royal Academy of Sciences, in 1775, is said to have been the only public mark of distinction he received in his native land. He was elected to the Society of Naturalists in Berlin, in 1778; and of the Academy of Sciences of Turin, in 1780, in the presence of his king, Gustavus III. His Majesty, it is said, had not heard much of Scheele before this, and was a little astonished, on hearing the eulogies passed upon the newly-elected member, to hear what a great man he had in his states. He was sorry that he had done nothing for him, and decided to make amends; he would confer an order upon him. The minister to whom he gave his directions was puzzled, for he, too, did not know Scheele. The order was conferred—but upon another Scheele than the chemist!
Scheele's collected works were published at Leipsic, in Latin, in 1788-'89, and in German in 1793. His papers in the Royal Academy have been translated into English by Thomas Beddoes, and are published under the title of "The Chemical Essays of C. W. Scheele."
On the 21st of May, 1886, the one-hundredth anniversary of Scheele's death, the people of Köping held an imposing celebration in memory of the man who had distinguished their town by making it the chosen home of one of the founders of the modern science of chemistry; and the representatives of science in Sweden, Germany, France, Switzerland, and other countries, expressed their sympathy in the occasion in appropriate messages.
