I have endeavored to present the subject in a condensed but general way without burdening you with technical details of species, genera or life history. The subject is a vast one and to which the best minds of the scientific world are devoting themselves. To those who are or may become interested in bacteriology and particularly to those who study the relation of these germs to disease, is held forth the reward which is sure to come to those who work persistently and intelligently. The method which I shall employ to-night is eclectic. Doubtless each investigator will find fault with some parts of the process and perhaps suggest a better one. The following, however, has in my hands worked well and given entire satisfaction, so far as I know, to those who were and are most interested. The apparatus necessary is as follows: One two-inch glass funnel. One package filter papers to fit same. Four medium size test tubes. Two glass or porcelain staining glasses. One glass or agate mortar and pestle. One cover holder. One pair pincetts. One alcohol lamp. Package of wooden toothpicks. The cover holder may be easily made by taking a piece of thin platinum, two inches long and one-eighth wide, splitting one end for half an inch up and bending into a Y shape, then lashing to a small handle (I use a match). This little tool is most convenient for floating cover glasses in staining fluids. The reagents necessary are as follows: A five per cent. solution of nitric acid in alcohol (95 per cent.). Saturated alcoholic solution of fuchsine. Saturated alcoholic solution of methyl blue. Small quantity of alcohol, 80 to 95 per cent. Pure colorless aniline oil (anilin). The method is as follows: First pour enough aniline into a test tube to cover the bottom and half fill with water, shake violently for two minutes, and filter through funnel, which has previously had wet filter paper fitted. It is essential that the filter paper be saturated with water, else the aniline oil will separate during filtration. Our next step is to deposit specimen of sputum in mortar (if very viscid, add a few drops of water), and triturate thoroughly in order to break up encapsulated colonies, and distribute evenly through the specimen.