It is hard, but it is one of the strongest elements in the Pasteur spirit of scientific research. Evidently Doctor Roux has learned to practise it vigorously. "In the same way that we are investigating diphtheria and cholera," continues the doctor, "we are studying other diseases. But one cannot get a fair idea of what the Pasteur Institute does by any other means than looking at its organizations. There is a great deal done here besides original investigation. In the first place, we are an absolutely independent and free institution. The money was given by popular subscription and without conditions. "The entire lower floor is devoted to practical work. There are performed the inoculations for hydrophobia on an average of some seventy a day. The practical department is not, however, confined to the treatment of hydrophobia. There are prepared the vaccines for all those diseases of animals which M. Pasteur has proved can be cured by inoculation, such as chicken cholera, splenic fever, and _rouget_ of swine. [Illustration: A GROUP OF PATIENTS.] "Quantities of virus are sold constantly to farmers for vaccinating their stock. It is these sales which help support the institution. It is an example of science living by science. "Here on this floor we do our instructing. In the lecture hall across the way M. Ducloux gives his lessons on microbic chemistry, studies the process of fermentation, microbic poisons, all phases, in short, of biological chemistry. "My work is lectures on, and experiments illustrating, the technique of the microbic method. Those who follow the courses are divided into two classes, students who simply follow the courses and repeat the experiments in the general laboratory, and the savants who conduct original researches here. The latter are furnished each with a private laboratory in the third story. Here for a merely nominal rent they can have the exclusive use of a laboratory furnished with all necessary apparatus, and can pursue whatever class of investigation pleases them." "And you have many students?" "We have always fifteen or twenty, and from all parts of the world. Look at my roll." The doctor rose and drew out from the mass of pamphlets and papers on his table a big roll-book. "I have the names of those who have taken my lectures. Here is an Egyptian, many Russians, a Turk, numbers from South America, from Canada, from the East, from everywhere. Let us look for your compatriots." Doctor Roux ran his finger down the pages. "Here is one, Doctor Orchinard of New Orleans. Here another, Doctor Tabadie of New York; and then there is Kenyoun of the United States Marine Service. But there have been more students in the institution from South America than from North. [Illustration: THE LIBRARY.]