Page:Popular Science Monthly Volume 75.djvu/298

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294
THE POPULAR SCIENCE MONTHLY

temperature and moisture, is somewhere between 2 million and 10,000 million ohms.[1]

It is conceivable that the grains of wheat exhumed with Egyptian mummies would scarcely have retained their germinating power after so many centuries had not nature clothed them with their insulating shells, and passing from these diminutive little lives of eggs, grains and cells, it is conceivable that this globe that we inhabit would itself become a moving sepulchre, devoid of all molecular transformations of energy, were it not for the external envelope of insulating atmosphere with which it is clothed. Without this insulation the energy of solar light and heat would no longer be transformed into things of beauty and life; but would at once be dissipated into the abysses of space and our earth would probably become as dead as the moon, which has no insulating covering, and, consequently, upon whose face, within the memory of man, no single change of feature has been observed.

In the foregoing discussion my purpose has been to lay the foundation for a modified definition of life. Every one is familiar with Spencer's definition, viz:

Life is the definite combination of heterogeneous changes, both simultaneous and successive, in correspondence with external coexistences and sequences.[2]

Never, perhaps, did human language attempt to express so much in so few words. In fact it is so condensed as to be difficult of comprehension. If the definition had been given first, few of us would ever guess that life was the thing it intended to define.

On page 80, Spencer says:

The broadest and most complete definition of life will be: the continuous adjustment of internal relations with external relations.

De Blainville said:

Life is the twofold internal movement of composition and decomposition at once general and continuous.

Criticizing this definition, Spencer remarks:

It describes not only the integrating and disintegrating processes going on in a living body, but it equally well describes those going on in a galvanic battery which also exhibits a two-fold internal movement of composition and decomposition at once general and continuous.[3]

At the time Spencer wrote (1866), biology was not sufficiently advanced for him to realize that every cell in the body really was a minute electric battery, and that the coordinate and simultaneous action of millions of these batteries made up together the living body of a complete animal.

  1. Science, December 4, 1908, p. 812, and Bulletin 99, 1907, Bureau of Plant Industry, U. S. Department of Agriculture.
  2. "Principles of Biology," p. 74.
  3. "Principles of Biology," p. 60.