The Society of Arts in 1830, received a communication from Dr. Bostock, in the course of which he stated that the "tannin, mucilage and extractive matter are without doubt the principal causes of the difficulty which is encountered in the formation of a perfect and durable ink and for a good ink the essential ingredients are gallic acid and a sesqui salt of iron." Owing to his working with galls he was unable to make decisive experiments, but he concludes, and that rightly, that in proportion as ink consists merely of gallate of iron, it is less liable to decomposition and any kind of metamorphosis. In 1831 the Academy of Sciences in France took up the matter and designated a committee composed of chemists with instructions to study the subject of a permanent ink. After long research it reported that it was unable to recommend any better ink than the tanno-gallate of iron one then in use, but "it should be properly compounded." Peddington investigated, 1841-48, the ancient MSS. collected by the Asiatic Society of Bengal, Calcutta, and published the results in "Examination of Some Decayed Oriental Works in the Library of the Asiatic Society," which are of much interest as relating to "mineral" inks, the "gall" inks being unknown in Asia after the twelfth century. Up to thirty-five years ago, the manufacture of "gall" inks necessitated a complicated series of processes and long periods of time to enable the ink to settle properly, etc. It was Professor Penny of the Anderson University who suggested the way to avoid one of the processes pertaining to ink-making by utilizing the known fact, that tannin is more soluble in cold than in warm or hot water. It was adopted all over the world and revolutionized the manufacture of ink, by doing away with boiling processes and hot macerations of ingredients. With hardly in exception the best tanno-gallate of iron ("gall") inks are now "cold" made. CHAPTER XIII. STUDY OF INK. INVESTIGATIONS BY STARK OF INK QUALITIES COVERING A PERIOD OF TWENTY-THREE YEARS--ABSTRACT FROM HIS REPORT OF 1855--DR. CHILTON EXPERIMENTS IN NEW YORK CITY 1856--ACTION OF THE PRUSSIAN GOVERNMENT IN 1859 AND EMPLOYMENT OF AN OFFICIAL INK--WATTENBACH'S GERMAN TREATISE ON THE ARCHIVES OF THE MIDDLE AGES--WILLIAM INGLIS CLARK ATTEMPTS TO PLACE THE MANUFACTURE OF INK ON A SCIENTIFIC BASIS--SUBMITS HIS VALUABLE RESEARCHES AND DEDUCTIONS TO THE ENINBURGH UNIVERSITY IN 1879--SCHLUTTIG AND NEUMANN IN 1890 ESTABLISH A STANDARD FORMULA FOR IRON AND GALL INK--NAMES OF SOME INK INVESTIGATORS OF THE NINETEENTH CENTURY. DR. JAMES STARK, a famous chemist, submitted the results of twenty-three years of investigations of writing inks in a paper read by him in 1855 before the Society of Arts, in Edinburg, Scotland. The following is the abstract as printed by the London Artisan at the time: