184 THE REIGN OF LAW. 



bably, like all other phenomena, by way of Natural 

 Consequence out of some combination of forces 

 which are the instruments employed. We have 

 no knowledge what these forces are, but we can 

 imagine them to be worked into a law of assimi- 

 lation, founded on some such principle as that 

 which photography has revealed. It is true that 

 Man has not yet discovered any process by which 

 the tints of Nature can be transferred, as the 

 most delicate shades of light can be transferred, 

 to surfaces artificially prepared to receive them. 

 Such a process is, however, very probably within 

 the reach even of human chemistry, and it is one 

 which is certainly known in the laboratory of 

 Nature. The Chameleon is the extreme case in 

 which the effect of such a process is proverbially 

 known. Many fish exhibit it in a remarkable 

 degree, — changing colour rapidly in harmony with 

 the colour of the water in which they swim, or of 

 the bottom on which they lie. The law on which 

 such changes depend is very obscure, but it appears 

 to be a natural process, as constant as all other 

 laws are ; that is, constant whenever given con- 

 ditions are brought together. It is possible that 



