15
have been shown to be modes of motion of material particles. It is not surprising, therefore, that the "vital forces" should have been considered to be correlated to them, and that eminent physicists should have tried to reduce vital phenomena to manifestations of purely physical energies.
Whatever may be the result of these speculations, the principle of the conservation of energy is one that may assuredly be applied with great effect to the solution of many vital problems.
Physiologists have already calculated the equivalents of force which may be produced by the combustion of fuel in the body, and Dr Frankland has ascertained the heat value of many kinds of food.
On the other hand, M. Barral has given an approximate estimate of the different amounts of force lost in different ways[1].
Nor are these mere abstract investigations, without immediate practical application. To take one instance only — those who are now cast down by the many defeats which have lately befallen our University Boat in its contests with Oxford, might perhaps discover the true meaning of over-training, by applying practically the results obtained by Messrs Fick and Wisliscenius[2], and by noting the kind of food shown by Drs Frankland[3] and Haughton[4] to be the best adapted for sustaining prolonged muscular exertion. They would probably find that courage and nervous energy would be none the worse for the support of a properly devised dietary.
But many other questions have been brought under the
- ↑ Thus from 1 to 2 per cent of power is given out in the heat of the excrements; from 4 to 8 per cent in the heat of the breath; from 20 to 30 per cent in the evaporation of water from the surface; and from 60 to 75 per cent in conduction and radiation and mechanical work.
- ↑ Phil. Magazine, Vol. xxxi. p. 485.
- ↑ See Appendix (2) to the Croonian Lectures for 1868.
- ↑ Address on the Relation of Food to Work. Oxford Meeting of Brit. Med. Association.
