328 



SCIENTIFIC .RECREATIONS. 



and the combination of the two'bodies will be instantly brought about, making 

 a violent explosion. Make a small spiral of platinum red-hot in the flame of 

 a lamp, having suspended it to a card ; then plunge it quickly into a glass 

 containing ether, and you will see the metallic spiral remam red for some time, 

 while in the air it would cool immediately. This phenomenon is due to the 

 action of oxidation which the platinum exercises over the fumes of ether. 

 This curious experiment is known under the name of the lamp without a 

 flame. This remarkable oxidizing power of platinum, which has not yet been 

 explained, was formerly designated by the title of catalytic action. But a 



Fig. 317. Discolouration of periwinkles by sulphuric acid. 



phrase is not a theory, and it is always preferable to avow one's ignorance 

 than to simulate an apparent knowledge. Science is powerful enough to be 

 able to express her doubts and uncertainties boldly. In observing nature 

 we find an experience of this, and often meet with facts which may be put 

 to profit, and become useful in application ; nevertheless it is often the case 

 that the why and the wherefore will for a long time escape the most 

 penetrating eye and lucid intelligence. It is true the admirable applica- 

 tions of science strike us with the importance of their results, and the 

 wonderful inventions they originate; but if they turn to account the observed 

 facts of nature, what do they teach us as to the first cause of all things, 

 the wherefore of nature ? Almost nothing. We must humbly confess our 

 powerlessness, and say with d'Alembert : " The encyclopaedia is very abun- 

 dant, but what of that if it discourses of what we do not understand ? " 



