1895.J MICROSCOPICAL JOURNAL. 295 



our planet and the play upon them of chemism, of light, 

 heat, electricity, cohesion, tension and the other mani- 

 festations so familiar to all ? And yet, who is there 

 that for a moment believes that aught of matter or 

 energy was created in the different stages of the evolu- 

 tion ? They appeared or were manifested just as soon 

 as the conditions made it possible. So it seems to me 

 that the energy called Life manifested itself upon this 

 planet when the conditions made it possible, and it will 

 cease to manifest itself just as soon as the conditions 

 become sufficiently unfavorable. It was the last of the 

 forms of energy to appear upon this j)lanet, and it will 

 be the first to disappear. 



In brief, it seems to me that the present state of physi- 

 cal and physiological knowledge warrants the assump- 

 tion, the working hypothesis, that life is a form of 

 energy different from those considered in the domain of 

 physics and chemistry. This form of energy is the last 

 to appear upon our planet, last because more conditions 

 were necessary for its manifestions. It, like the other 

 forms of energy, requires a material vehicle through 

 which to act, but the results produced by it are vastly 

 more complex. Like the other energies of nature it does 

 not act alone. It acts with the energies of the physicist, 

 but as the master; and under its influence the mani- 

 festations pass infinitely beyond the point where for the 

 ordinary energies of nature it is written ' thus far and 

 no farther.' 



It can be stated without fear of refutation that every 

 physiological investigation shows with accumulating 

 emphasis that the manifestations of living matter are 

 not explicable with only the forces of dead matter, and 

 the more profound the knowledge of the investigator 

 the more certain is the testimony that the life energy is 

 not a mere name. And, strange to say, the physicist 



