[From yature, Vol. X.] 



LXVII. Grove's " Correlation of Physical Forces*" 



THKKE are few instances in which anyone whose life has not been exclu- 

 sively scientific has made such valuable contributions to science as those of Sir 

 W. R. Grove. His nitric acid battery, to the invention of which he was led, 

 not by accident, but by a course of reasoning, which in the year 1839 was as 

 new as it was original, is a contribution to science the value of which is proved 

 l>y its still surviving and continuing in daily use in every laboratory as the 

 most powerful generator of electric currents, while hundreds of batteries invented 

 since that of Grove have fallen into disuse, and become extinct in the struggle 

 for scientific existence. 



The gas battery, though not of such practical importance, is still of great 

 scientific interest, and the collection which we have before us of those contri- 

 butions to science which took the form of papers, tempts us to indulge in 

 speculations as to the magnitude of the results which would have accrued 

 to science if so powerful a mind could have been continuously directed with 

 undivided energy towards some of the great questions of physics. 



But the main feature of the volume is that from which it takes its name, 

 the essay on the Correlation of Physical Forces, the views contained in which 

 were first advanced in a lecture at the London Institution in January 1842, 

 printed by the proprietors, and subsequently more fully developed in a course 

 of lectures in 1843, published in abstract in the Literary Gazette. This essay 

 has a value peculiar to itself. Though it has long ago accomplished the main 

 point of its scientific mission to the world, it will always retain its place in 



* Tlte Correlation of Physical Forces. Sixth edition. With other Contributions to Science. 15y 

 the Hon. Sir W. R. Grove, M.A., F.R.S., one of the judges of the Court of Common Pleas. (London: 

 Longmans, 1874.) 





