ZWARTKOPS BORE AND THERMAL SPRING. 1 27 



The following is the result:— vj^'^ 



Metal. Before. After. ' *o ' 



Copper 564 grains 571 grains. g- jfr *»>£>"* 



Copper, tinned 511 grains 516 grains. (^ L 1 8 I 



on sides .. \V\ ^ ^ 



Brass .] 312 grains 304 grains. V^y\ 



Galv. Iron .. 466 grains 420 grains. 



Zinc 220 grains 185 grains. 



Lead 2.172 grains 2.096 grains. 



Aluminium . . 160 grains 205 grains. 



Some larger samples of iron piping were put in the water 

 at the same time and are still there. The galvanised iron tubing 

 seems to have suffered less deterioration than the others, but none 

 of the larger samples were weighed. 



Modern Tendency of Physical Science — On 

 the 17th October last Sir Oliver Lodge delivered, before the 

 Chemical Society, the Becquerel Memorial Lecture, in which he 

 summarised the influences on the course of physical science of 

 the epoch-marking discovery made by Henri Becquerel, in 1896, 

 that uranium compounds possess the power of emitting rays 

 analogous to those associated with the name of Rontgen. Some 

 of the lecturer's remarks are extracted below : — 



" The atmosphere of physical science at the present time 

 is rather a strange one. . . . There was a time, within easy 

 memory, when the progress of discoverv was placid and peaceful. 

 It seemed to proceed along well-worn channels, and to be based 

 upon the most thoroughly substantial knowledge of the past. 

 .... Philosophers and biologists attended to their own fields 

 of work, and so, for the most part, did mathematicians and 

 chemists ; each group proceeding on its own lines, without much 

 regard for the others. Now all is changed : — 



" Chemistry has borrowed the idea of evolution from bio- 

 logy, and is trying to extend it from the origin of species to the 

 origin of atoms; though some chemists reject all this as baseless 

 speculation, and pour modulated scorn upon the few recent dis- 

 coveries which physicists are willing to accept. 



" Biologists have been ultra-speculative in their quest for 

 the origin of life, and are turning their attention to metaphysics 

 and philosophy, some of them in an energetic and pugnacious 

 manner. 



" Mathematicians disport themselves destructively among 

 what have seemed the realities, the very data, of physics ; dis- 

 tributing an atmosphere of doubt and hesitation almost equally 

 over space, time, matter, and motion, and treating the ether with 

 a veiled contempt. 



" Philosophers question the correctness of our most funda- 

 mental laws — doubting, for instance, even the conservation of 



