The Influence of Lord Rutherford
One would have hoped that the father of nuclear science, Lord Rutherford, would have conducted some experiments in nuclear science in his early work while a student at Canterbury College, Christchurch. New Zealand cannot claim such distinction. Ernest Rutherford's first paper published in the Transactions of the New Zealand Institute in 1894 was on the magnetisation of iron by high-frequency discharges. His second paper, published also in New Zealand in 1895, was on magnetic viscosity. Even his third paper which he produced when he was studying at Trinity College, Cambridge, as an 1851 Exhibition Scholar, was on magnetic detection of electrical waves. His fourth paper, published in the Philosophical Magazine in 1896, studied the ionisation of gases, first by roentgen rays and then by ultra-violet light. This led him eventually to the rays from the radioactive element uranium and the electrical conduction produced by such rays. It was just five years after his first experiments in New Zealand under Professor A. W. Bickerton and at Cambridge under Sir J. J. Thompson that he established himself along the path that made him one of the greatest figures in the history of science.
Lord Rutherford visited New Zealand in 1914 and at the Wellington Town Hall gave what must be the most historic lecture ever delivered to a New Zealand audience when he explained and demonstrated his nuclear theory of atoms by a magnetic model which illustrated repulsion between the oncoming alpha particle and the newly discovered nucleus of matter. In 1924 he returned for the last time to his native country. While Rutherford never worked in New Zealand, there came from his laboratories to our shores men whose scientific calibre was reflected in the positions each attained. Such scientists were Professor D. C. H. Florance, professor of physics at Victoria University College, who worked as a student under Rutherford at Manchester, as did Sir Ernest Marsden, past secretary of the D.S.I.R., who did the original famous experiment which led Rutherford to the discovery of the nucleus of matter. Dr D. H. Black worked under Rutherford at Cambridge but never returned to New Zealand. Dr L. Bastings, who recently retired from the Dominion Physical Laboratory, is still actively engaged in promoting the importance of physics in building research. To these men Rutherford was not only a great teacher and scientist but also a valued counsellor and friend. His spirit – the pursuit of scientific truth – they brought with them to New Zealand, his advice and friendship they passed on to a younger generation of New Zealand scientists. With the stimulus of such an outstanding New Zealand scientist overseas, it was not long before the applications of the scientific principles he pioneered found their way to New Zealand.
In 1906 J. H. Howell examined a number of New Zealand mineral springs and deposits in an attempt to explain their therapeutic properties in terms of the known germicidal properties of radioactive substances. This paper was followed in 1909 by an examination of the radium content of igneous rocks from the subantarctic islands of New Zealand by C. C. Farr and D. C. H. Florance of Canterbury College, and their findings were communicated by Rutherford to the Philosophical Magazine of London. Rutherford sent a solution containing 3·14 10-9 gram of radium to Farr to be used in the standardisation of his electroscope. Interesting rocks tested were an andesite from Ngauruhoe, lava from the crater of Mount Erebus, and a meteorite that fell at Mokoia in 1908. These specimens were shown to contain amounts of radium of the order 0·3 to 26 10-12 g radium per gram of rock.