Page:Popular Science Monthly Volume 50.djvu/153

Rh  municipalities and all public works on which he may be engaged.

An India-Rubber Famine.—The world's consumption of India rubber has been increasing so enormously during the past few years that the time does not seem to be far distant when the demand will greatly exceed the supply. The bicycle is of course responsible for a large part of this increase, and, as the pneumatic tire is becoming more of a necessity every day for all city vehicles, there promises to be a still greater demand hereafter. It is stated that only within the last year has there been any attempt to regulate the gathering of caoutchouc and to stop the wanton destruction of the tree, which it seems is usually cut down, so as to facilitate the collecting of the sap. This puts an end to the productiveness of whole districts every year, and, as it has been found that by properly made incisions about two pounds of rubber can be gathered from each tree annually, without in any way interfering with its growth or life, vigorous attempts are called for, and it is stated are being made, to regulate the treatment of the trees. Owing to the danger of a rubber famine, several chemists in both France and Germany have been working on methods for the artificial production of India rubber, and several new processes have already been announced. Attention has also been turned to the balata, a South American tree. This balata rubber, while not so good for insulation and other purposes as caoutchouc, is yet specially adapted for a great many uses, such as machinery belting, mackintoshes, surgical appliances, etc., and British Guiana has developed quite an export trade in it, the annual quantity amounting to over three hundred thousand pounds. 

number of the American Medical and Surgical Bulletin contains an article on the artificial generation of ozone for purifying the air in our public schools. In many cases the schoolroom air is so stale and depressing that before the children have been in it half an hour all their brightness and vim has disappeared, they become listless and sleepy, and are in the worst possible condition for study. This alone would be bad enough, but breathing this vitiated air renders them more vulnerable to the attacks of pathogenic germs, some of which are sure to be present in such a favorable location. Ozone is markedly germicidal and stimulating, and the suggestion, although not a new one, seems worthy of attention.

has been decided to erect in one of the squares of Paris a monument to Pasteur, and to make the enterprise an international one. Consequently, the people of all countries will be given an opportunity to participate in the subscriptions. The Paris committee is under the presidency of M. J. Bertrand, Perpetual Secretary of the Academy of Sciences, and has among its honorary members the President of the Republic and his Cabinet, and about one hundred and sixty prominent men of the French nation in all walks. A committee has been formed in the United States, at Washington, with Dr. D. E. Salmon as chairman and Dr. A. E. de Schweinitz as secretary, which gladly accepts the privilege of organizing the subscription and of receiving and transmitting the funds which are raised. "We believe it is unnecessary," the committee says in its circular, "to urge any one to subscribe. The contributions of Pasteur to science and to the cause of humanity were so extraordinary and are so well known and so thoroughly appreciated in America that our people only need the opportunity in order to demonstrate their deep interest." Subscription blanks will be supplied by the committee, and no one who can not give a large sum need be deterred from giving a small sum. The committee's address is at the Cosmos Club, Washington, D. C.

Biologisches Centralblatt, conducted by Drs. J. Rosenthal, M. Rees, and E. Seleuka, and published semimonthly at Leipsic by Eduard Besald, aims to keep its readers in current with the progress of the biological sciences, and to inform the students of single branches of what is going on in the other and related branches. With a view to that object it presents original communications, particularly those embodying the results of 