Volume 1

The book of nature study / edited by J. Bretland Farmer ; assisted by a staff of specialists.

Date:
[1908?]-1909
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: The book of nature study / edited by J. Bretland Farmer ; assisted by a staff of specialists. Source: Wellcome Collection.

    23/276 (page 5)
    crystal and the growing caterpillar, the piece of potassium and the whirligig beetle.] (6) From the Physicist's Point of View.—The living creature is like some wonderful kind of engine or machine, but it is more efficient. Like an engine it transforms matter and energy, but it does so more economically. It is a self-stoking, self-repairing, self-preservative, self-adjusting, self-increasing, self-reproducing engine ! It has a remarkable power of accumulating and storing energy, of taking rests, of “ acting of its own accord/’ of profiting by experience. In comparing a living creature with a machine, which is a very useful analogy to work out with pupils advanced enough to understand it, it should always be remembered that a machine is hardly a fair sample of the inorganic world, since it is the embodiment of a human thought. (c) From the Chemist's Point of View.—The component elements of living creatures are just the common elements found in their surroundings, but the “ make-up ” of the compounds which form the physical basis of life is very intricate. The chemical elements which enter into the composition of organisms are : carbon, hydrogen, oxygen, nitrogen, sulphur, phosphorus, chlorine, potas- sium, sodium, calcium, magnesium, and iron ; and there may be others. Of these elements the first five enter into the com- position of the most characteristic of organic compounds which are invariably present in living creatures, namely, the proteids, such as the albumin of eggs, the haemoglobin of our blood, or the gluten of wheat. It is probable that living matter is a mixture of proteids, owing its virtue to their co-operative interaction, just as the secret of a firm’s success may depend not on any one partner by himself, but on the combination of talents. In the living body we can trace a number of chemical processes which follow one another in a sort of routine. We can trace the raw material of food being digested and incorporated into the living body ; we can detect the breaking-down of complex sub- stances and the getting rid of waste; but we cannot redescribe the unified life of the creature in terms of chemical formulae. It seems certain, however, and this is perhaps the most significant feature from the chemist’s point of view, that there is a twofold