The managers of the infirmary of course did all in their power to remedy this insalubrious state of things. They poured large quantities of carbolic acid and quicklime upon the ground, considering this a less dangerous proceeding than to attempt the removal of the putrefying mass; they covered the ground with an additional thickness of earth, and adopted other measures. The hospital itself was far from being well situated in other respects. It abutted against the old Cathedral Churchyard, much used for the “pit burial” of paupers in a most deleterious state of aggregation. Yet during the two years and a quarter intervening between the Dublin address and Mr. Lister’s leaving Glasgow for Edinburgh, his new antiseptic system continued in the main as successful as before. In the course of the year 1864 Professor Lister had been much struck with an account of the remarkable effects produced by carbolic acid upon the sewage of the town of Carlisle, the admixture of a very small proportion not only preventing all odour from the lands irrigated with the refuse material, but also destroying the entozoa which usually infest cattle fed upon such pastures. His attention having been for several years greatly directed, as we have seen above, to the subject of suppuration, especially in its relation to decomposition, he saw that such a powerful antiseptic was peculiarly adapted for experiments with a view to elucidating that subject, and thus the applicability of carbolic acid to the treatment of compound fractures occurred to him. The antiseptic system was put into practice in the Glasgow Infirmary in March 1865, but at first applied almost exclusively in compound fractures (or those in which there is an external wound) and abscesses. From 1867 it was employed for almost all surgical cases. It arose out of Mr. Lister’s study of Schwann and Pasteur’s germ theory and the experiments connected with them. He repeated many of the experiments, and devised new methods calculated to test whether they were capable of explaining the phenomena of putrefaction. These sufficed to prove definitely that in putrefaction the development of such organisms as the microscope could detect, and the concomitant putrefactive changes, were occasioned by minute germs suspended in the atmosphere. Professor Tyndall’s beautiful experiments, by which he demonstrated the perfect manner in which cotton wool filters the air of its suspended particles, led to the idea (suggested by Dr. Meredith of the Indian service to Mr. Lister) that cotton wool might be used with advantage as an antiseptic dressing. The cotton wool must itself be rendered pure of germs by some antiseptic agency, for by the theory the air within it must contain germs. But the main feature upon which Mr. Lister for a long time relied was the copious use of carbolic acid in such a form as to prevent the occurrence of putrefaction in the part concerned.