PHILOSOPHICAL INSTITUTE.

Press, Volume LXVII, Issue 14094, 13 July 1911, Page 9

PHILOSOPHICAL INSTITUTE.

The Philosophical Institute of Canterbury met in tho old Chemical liaboratory at Canterbury College lastnight, Mr A. M. Wright,, president, being in the chair. * . An address was given by Mr T>. C HL Floranoe on "Recent Advances in Radio-Activity." Tho speaker said tliat radium, thorium, and uranium possessed tho property of emitting emanations without apparently reducing their volume. This was lirst discovered by Becquerel in 1896 in regard to uranium. Madamo Curie then set about investigating whether there were any other substances of a similar nature, and sho discovered radium in pitch blende or uranium ore. Last year she announced she had obtained radium in its pure state. Radium at present cost £18 a milligram, and was in great demand among doctors. Radio-active bodies caused air to lose its insulating powers and to become a partial conductor of electricity, and this fact enabled the electroscope to measure radio-ac-tivity. The speaker illustrated theeffect of radium on tho electroscope by an interesting experiment. He went on to illustrate by means of tne spintharoscope another property of radioactive motives, namely that of producing fluorescence. This striking littlo •instrument was passed round in darkness, and tho scintillations of the atoms of matter were viewed with wonder. Tho lecturer stated that by the aid of this instrument an observer could sit in darkness and count tho atoms passing oil tho radium. From the study of radium much could be learned in regard to tho nature of matter. Scientists had discovered that a link was missing between uranium and radhlm, and ionium had proved to be the direct parent of radium. At present, Madame Curio was trying to procure lead from polonium. The speakor answered a number of questions, and was accorded a hearty vote of thankß. Dr. Chilton read a paper by Mr G. Archcy, student assistant in the biological laboratory, on fne hydra, one of tho lowest forms of life. A vote of thanks was passed. Mr E. R. Waite spoke briefly on certain fishes found in the waters of the Kermadec Islands. At tho next meeting, which will Ih> held on 2nd August. Xh*. Cockayne will read a paper on various theories of evolution.