SCIENTIFIC NOTES.

Press, Volume L, Issue 8581, 7 September 1893, Page 3

SCIENTIFIC NOTES.

— «fc 1 An interesting contribution to the science of microbes has been recently made by Messrs d'Arsonval and Charrin, who«e results have been brought before the Academic dcs Sciences at Paris. M. d'Arsonval has constructed a solenoid, in the coils of which an alternating, current of enormously rapid frequency (800,000 oscillations per second) is caused to flow. In the hollow of the solenoid a "cultivation " of pyocyanogen bacteria was placed, . with a view to seeing what effect, if any, the induced secondary currents would have upon, the organism. Like most kinds of vegetable life, the bacteria throve and flourished abundantly under the electric influence; but a marked change was produced on their chrome-' genie powers. Bacteria of a brilliant blue-green colour gradually became pale Inside the coils, until the colour almost entirely died out. lb is thought thai there may be grounds for important research here, as the virulence of many germs is bound up with their colour, and times of great electrical disturbance, such as thunderstorms, might be expected in consequence to have a marked effect on the course of certain diseases. The cordling of milk and similar phenomena are possibly not. unconnected with this discovery.— Pall Mail Gatette. It how does nut seem improbable that, when by the power of thought an image is evoked, a distinct reflex action, no matter how weak, is exerted upon certain ends of the visual nerves, and therefore upon the retina. Will it ever, be within human power to analyse the condition of the retina when disturbed by thought or reflex action, by the help of some optical or other means of such sensitiveness that a clear idea of its state might be gained at any time? If this were possible, then the problem of reading one's thoughts with precision, like the characters of an open book, might be much easier to solve than many problems belonging to the domain of | positive physical science in the solution of which many, if not the majority, of scientific men implicitly believe.— X€Ma Tesla. in the (JVew? York) Electric World. The Lancet says:—A writer In Electnti S has made the interesting observation that I there is a difference of potential between the water and gas pipes in all houses, ana that If one terminal of a telephone fa joined to the water pipe, a crackimg sound is heard In the telephone on lightly touching the gas pine, which, of course, indicates the passage of the current. By substitutinga galvanometer for the telephone, it is fou nd that the negative pole Is formed by the gas pipe, the galvanometer deflection being permanent and constant in amount daring several months, though there is a slight diurnal variation. These experiences have led to the suggestion that the pipes must be fairly well insulated from one another, and might really act a* conductors for telephonic communication. As a matter of fact, it is stated that conversation was successfully carried on without any other conductor between two houses at a distance of 100 metres apart, the microphone used in the experiment being joined to three bichromate cells.