14 NATURAL SCIENCE. Jan.. 



those who, Hke The Times, denounced it at the time, accept it to-day. 

 Tyndall first went to the meetings of the Association at Ipswich in 

 1 85 1, and for some years was a regular attendant ; in 1867 he delivered 

 the "Working Men's Lecture," taking as his subject, "Matter and 

 Force"; he was President of the Mathematical and Physical Section 

 in 1868, when his address dealt with " Scientific Materialism." 

 In 1870 he was the lecturer for the year, and read his famous essay 

 on the " Scientific use of the Imagination." 



In later years Tyndall was not so prominently before the public, 

 especially afrer his marriage, in 1876, to the Hon. Louisa Hamilton, 

 the eldest daughter of the late Lord Claud Hamilton. He spent 

 most of his time at his house at Haslemere, and went every summer 

 to his chalet, the Villa Lusgen, in Switzerland. In 1877, however, he 

 accepted the Presidency of the Birmingham and Midland Institute, 

 and gave as his inaugural address a lecture on " Science and Man," 

 by which he again roused the wrath of his theological opponents. 

 In 1887, he resigned his position at the Royal Institution, and was 

 entertained at a farewell dinner by what was described by Nature at 

 the time as the most representative gathering of English Science 

 that had ever been held. Since then he had written or lectured 

 but little, though the Orange blood that was in him led him 

 to enter into political warfare in opposition to the different Home 

 Rule schemes. Two years ago he was taken dangerously ill, but he 

 recovered, and he visited Switzerland this summer as was his wont. 

 He returned in October, and, in consequence of a tragic accident, 

 peacefully passed away on the 5th December. 



It is difficult for one who is not a physicist to give any sketch of 

 Tyndall's work in science, as his main work lay in this department 

 of research ; but this I may be allowed to attempt, as physics do not 

 come within the domain of Natural Science. The first research was 

 upon " The Phenomena of a Water Jet," which was not, however, 

 published till 1851. The subject which he made especially his own 

 was diamagnetism, upon which he wrote about twenty papers, 

 commencing with a short note " On Diamagnetic and Magnecrystallic 

 Action," published in 1850 in the second volume of the Chemist, and in 

 the Reports of the British Association in the following year a more 

 detailed memoir on the same subject, entitled " Diamagnetism, the 

 polarity of the diamagnetic force, the magneto-optical properties 

 of crystals, and the relations of magnetism and diamagnetism to 

 molecular arrangement " ; this gained for him admission to the Royal 

 Society. Radiation was another question on which he did much 

 work. He took it as the subject of his " Bakerian " and "Rede" 

 Lectures in 1864 and 1865, when he announced his discovery of 

 " calorescence," in which, by altering the refrangibility of the ultra- 

 red rays of the spectrum, they can be rendered visible. This is 

 simply the converse of Stokes's well-known experiments on " fluores- 

 cence," by which the ultra-violet rays, after analogous treatment. 



