CoUingwood' s Ranibks in the China Seas 369 



tissue or of sarcode substance, which contractility is itself a vital act, seems 

 sufficient to produce the phenomena in question." (pp. 407, 408.) 



The nature of the phenomenon treated by Dr CoUingwood is a 

 very difficult one, and we should have liked to have had the views 

 of such an intelligent naturalist a little more developed as to the 

 modus operandi by which the luminous result is attained. No one 

 will dispute the position he has entrenched himself in, that if all 

 forces producing physical phenomena are corelated and convertible, 

 it may be due to any of them. But what we should have liked to 

 know his opinion upon is, which of them is in operation in any 

 particular case. They may all or any of them be mixed up with 

 it, but taking the phenomenon at a particular stage, what is its 

 then nature. When we see the ocean apparently on fire, is the 

 light real fire or is it not ? Are the animals which give it out 

 burning or not ? Is it slow combustion by chemical action, or is 

 it a phenomenon of electricity ? It comes very much to this — Is 

 there more than one source of light? Fire-light used to be 

 thought different from sun-light. We now know that they are 

 the same. Our own opinion is that there is only one source of 

 light, and that is chemical action — in other words combustion. 

 Combustion, indeed, is usually understood to be only another 

 word for oxydization. Hence, where there is no oxygen, it would 

 follow that there can be no combustion, and some examples of 

 phosphorescent and fluorescent light seem to exist under com- 

 bustions where there can be no oxydization. The light in such 

 instances may nevertheless be due to the presence of oxygen in 

 such small quantities as to escape our detection, or that light may 

 be produced by some analogous phase of chemical action where 

 something else takes the part and performs the duty of oxygen ; 

 and it seems not unreasonable to ascribe the phenomenon to one 

 or other of them until we have better data on which to go. 



Leaving such recondite physiological questions, let us turn to 

 some of the other more palpable and material subjects noticed by 

 Dr CoUingwood. The woodcut, fig. 2, is a representation which 

 he gives of the curious forms produced by the degradation of 

 sandstone rocks, on the south side of Kelung harbour, in For- 

 mosa. We should have been disposed to refer the appearance to 

 the action of the weather, but Dr CoUingwood ascribes it to 

 aqueous action. He says : — 



"The effect of aqueous action upon the sandstone rocks are veiy conspicuous in 

 some parts of Kelung harbour. Near the cave before mentioned, and im- 



