446 Professor Tyndall [May 3, 10, and 17, 



He denied them all power of true conduction, and tliougli Lis experi- 

 ments did not, and could not, prove this, they did prove that in the 

 propagation of heat through the liquids he examined, which were water, 

 oil, and mercury, conduction played an extremely subordinate part. 



Rnmford changes from time to time the tone of the philosopher 

 for that of the preacher. He seems filled with religious enthusiasm 

 on contemplating what he holds to be the wisdom and benevolence 

 displayed in the arrangement of the physical world. One fact in 

 particular excited tliis emotion. De Luc had pointed out that when 

 water is cooled, it shrinks in volume, until it reaches a temperature of 

 about 40° Fahr. At this point it ceases to contract, and expands when 

 cooled still further. The expansion we now know to be due to in- 

 cipient crystallisation, or freezing, which when it once sets in greatly 

 enhances the expansion. A consequence of this is that ice floats as a 

 lighter body upon water. This fact riveted the attention of Rumford, 

 and its obvious consequences filled him with the enthusiasm to which 

 I have referred. He was strong, but untrained, and his language 

 was not always such as a truly disciplined man of science would 

 employ. " Let me," he says, " beg the attention of my reader, while 

 I endeavour to investigate this most interesting subject, and let me at 

 the same time bespeak his candour and indulgencj?. I feel the danger 

 to which a mortal exposes himself who has the temerity to undertake 

 to explain the designs of Infinite Wisdom. The enter2)rise is adven- 

 turous, but it cannot surely be improjjcr." 



He " exphiins " accordingly ; and, notwithstanding his professed 

 humility, does not hesitate to brand those who fail to see with 

 his eyes as " degraded, and quite callous to every ingenuous and 

 noble sentiment." He indulges in excursions of the imagination 

 with a view of rendering clear the misfortunes that would accrue if 

 the arrangement of the world had been different from what it 

 is. " Had not Providence, in a manner which may be well con- 

 sidered as miraculous," stopped the contraction of water before 

 it reached its freezing-point, and caused it to expand afterwards, 

 a single winter would freeze every fresh-water lake within the 

 polar circle to a vast depth, '• and it is more than probable that the 

 regions of eternal frost would have sj^read on every side from the 

 poles, and, advancing towards the equator, would have extended its 

 dreary and solitary reign over a great part of what are now the most 

 fertile and most inLabitcd climates of the world ! " He expands 

 this thesis in various directions, the whole argument being based 

 on the assumption that " all bodies are condensed by cold, without 

 limitation, water only excepted." Repeated disaiipcnntments in such 

 matters Lave taught us caution. Legitimate grounds for wonder exist 

 everywhere around us; but wonder must not be cultivated at the 

 expense of truth. Brought to the proper test, the assumption on 

 which Eumford built his striking teleological argument is found to 

 be a mere quicksand. The fact that he adduces as unique is not an 

 exception to a universal law. There are other substances, to which 



