FREEZING AND THAWING. 71 



ever useful in their individual properties. The mere 

 production, the plant or the animal, however humble 

 and however common, is something wonderful compared 

 with what we can accomplish ; but when we look upon 

 it in its connection, and follow out the wonderful chain 

 of causes that lie between the projecting of the sun- 

 beam through the air, and the awakening into life of 

 the little insect which dances in that beam, we discover 

 a unity of operation and a diversity of effect, in which 

 Almighty power and infinite wisdom stand clearly dis- 

 played, thence too we learn science, and from that 

 how to act; and man is raised an hundred fold 

 in the scale of intellect and enjoyment. The single 

 matters are the museum, but this is the workshop : in 

 the former we may and must wonder, but it is in the 

 latter only that we can know ; although at the com- 

 mencement of our career we probably need the sensai 

 enticements of the one to allure us on to the other. 



The extreme slowness with which ice melts, in con- 

 sequence of the great heat required in the change of 

 form, and which passes latent into the water without 

 having any effect upon the thermometer, is just as 

 beneficent in the economy of nature, as the slowness of 

 the opposite change. If equal weights of liquid water 

 at different temperatures be mixed together, the tem- 

 perature of the mixture is half the sum of the two ; as 

 water at 32 and water at 172, would give a mixture 

 at 102. But with ice it is very different. If a pound 

 of that at 32 and in powder, so that the water may 

 act instantly upon it, be mixed with a pound of water 

 at 172, the temperature of the mixture would be only 

 32, or precisely that of the ice. If by the addition of 



