LIFE AS COMPARED WITH THE PHYSICAL FORCES. OO 



composition of protoplasm is very complex, and has not been 

 exactly determined (bat an advance has been made in this respect, 

 during the thirteen years which have elapsed, us Mr. Slater clearly 

 shows). It ma}', however, be stated that protoplasm is essentially 

 a combination of albuminoid bodies, and that its principal elements 

 are, therefore, oxygen, carbon, hydrogen, and nitrogen. In its 

 typical state it presents the condition of a semi-fluid-atenacious, 

 glairy liquid, with a consistence somewhat like that of the white 

 of an unboiled egg. While we watch it beneath the microscope, 

 movements are set up in it; waves traverse its surface, or it may 

 be seen to flow away in streams, and this not only where gravity 

 would carry them, but in a direction diametrically opposed to 

 gravitation ; now we see it spreading itself out oii all sides into a 

 thin liquid stratum ; and again drawing itself together within the 

 narrow limits which had at first confined it, and all this without 

 any obvious impulse from without, which would send the ripples 

 over its surface, or set the stream flowing from its margin. N'o 

 one who contemplates this spontaneously moving matter can deny 

 that it is alive. Liquid as it is, it is a living liquid; organless and 

 structureless as it is, it manifests the essential phenomena of life." 

 Such was the president's lucid description of protoplasm. But, as 

 I remarked shortly after his address was delivered, there is not 

 one phenomenon mentioned which has not its counterpart in the 

 merely physical world. Protoplasm is simply peculiar in combin- 

 ing the whole. 1. The chief elements of protoplasm, enumerated 

 by the professor, are equally contained in the sesqui-carbouate of 

 ammonia. 2. Its consistence may be stimulated by various 

 inorganic solutions, not to mention collodion. 3. And as to the 

 movements of protoplasm, in what do these differ from those of 

 the sea upon the shore, except in the matter of rhythm ? There 

 we have apparent expansion and contraction, and an upheaval of 

 the substance, which only science has taught us to be due to some- 

 thing outside itself. And if this be beside the mark, what are we 

 to say to the evaporation of water by the stimulus of heat, and the 

 condensation of vapour by cold ? What are we zo say to the 

 diffusion of gases and of liquids, and to their eudosmosis and 

 exosmosis through dead membranes ? What, moreover, are v/e to 

 say to the process of solution, by which a small portion of the 

 chemical compound mentioned above, placed at the bottom of a 

 tube a foot in length, can, by the simple addition of watei', be 



