Sixth Meeting: 7th September, 1910.
Present: Mr. A. M. Wright (Vice-President), in the chair, and fifty others.
New Member.—Mr. R. G. Ross.
Letter from Sir Joseph Hooker.—A letter was received from Sir Joseph Hooker acknowledging the receipt of the two volumes of the “Subantarctic Islands of New Zealand.” It was resolved that the Council of the Institute be instructed to preserve the letter in a fitting manner, and deposit it among the papers of the Institute as one of the most valued documents in its possession.
Address.—“Modern Views of the Constitution of Matter,” by Dr. H. G. Denham.
The lecturer said that two of the most important problems that remain more or less unanswered are the constitution of matter and the nature of electricity. A vast amount of experimental research has, however, led many of the ablest physicists of the world to the view that these two problems are very closely interwoven—in fact, that electricity and matter are really two manifestations of the same phenomenon.
The lecturer then proceeded to describe the experimental evidence that has led physicists to this conclusion, illustrating his remarks by experiments and lanternslides. After explaining the nature of the cathode rays, he proceeded to the more
recent work of Thomson, Lenard, Lorenz, and others, showing how these scientists have been able to establish the existence of negatively charged electrons in matter. The mass of these electrons has been found to have an exceedingly small value, being in fact only one-thousandth part of the hydrogen atom, which we had hitherto supposed to be the smallest part of matter capable of separate existence. Moreover, research has led to the interesting discovery that this mass is not mechanical, but electric in origin, and is really due to the rapid motion of a charge of electricity. Thomson has thus been led to put forward the tentative view that all matter is electric in origin, the atoms of all elements containing these negatively charged electrons in rapid rotation inside a positively charged sphere. These electrons are differently arranged in the atoms of the different elements, but the arrangement is always the same in the atoms of the same element. On this supposition it is possible to give a real meaning to the periodic table of the chemist; for a periodic arrangement of the electrons would necessarily lead to a periodic recurrence of many chemical and physical properties.
In conclusion, the lecturer quoted from the presidential address of Professor SIR J. J. Thomson to the British Association last year, wherein he expressed the opinion that the experimental work of the last decade had given new life to physics, but that many a difficult peak must yet be scaled before an outlook over the whole constitution of matter and of the universe can be hoped for.
At the conclusion a hearty vote of thanks was accorded to Dr. Denham for his address.