284 



NATURE 



[October 28, 1920 



Lancashire. The Cretaceous sea lay over Angle- 

 sey, and Cainozoic folding has carried its base 

 (p. 895) to some 700 or 800 ft. above the present 

 sea-level. No great warping is needed to prolong 

 this base over Snowdon, and the excavation of 

 the deep valleys of the highland is ascribed, like 

 the levelling of the " Menaian platform " {p. 783), 

 to Pliocene denudation. The contrast between 



Snowdonia and the lowland of Anglesey is not 

 due to differential erosion, but to the curve of 

 the Cainozoic anticline, rising to the east. 



The details of the glaciation of the island are 

 now for the first time adequately dealt with, and 

 with this last hint of the additions made by Mr. 

 Greenly to British geology, our notice must, ev^r 

 gratefully, conclude. 



Food Requirements and the Minimum Wage. 



A WELL-KNOWN and trusted Labour leader 

 remarked, not very long age, to the writer 

 of the present article, apropos the scientific assess- 

 ment of food requirements, that "Science leaves 

 me cold." Labour, in common with other parties 

 in the community, has to learn that, unpalatable 

 or no, scientific truth must be faced squarely. 

 Unless the conduct of affairs be laid securely on a 

 sound, scientific basis, and not on sentimentalism, 

 the social edifice will collapse. It is constantly 

 forgotten that the scientific dictum of to-day 

 usually becomes the hackneyed commonplace of 

 to-morrow. 



Much as the recent proposal to base wages on 

 a sliding scale, rising and falling with the cost of 

 living, is resented, it is an absolutely sound 

 doctrine, and probably the only practicable base 

 to work from without inflicting undue hardship 

 upon the community at large. Many workers 

 seem to resent the utilisation of this base on the 

 ground that it would reduce them, in their 

 opinion, to the level of animals. This is a per- 

 fectly unsound deduction, and not only is it un- 

 sound ; it is unwarranted. The introduction of 

 such a scientific assessment of wages does not 

 reduce the status of the worker. 



We all have a right to live, and life is main- 

 tained by an adequate ingestion of food. The 

 only practicable basis for the fixation of the level 

 of the minimum wage would seem to be the cost 

 of living. It has been contested by many people 

 who are unacquainted with the methods of science 

 that as all humanity is neither of the same sex 

 nor of equal age and size, and as the work per- 

 formed by various classes of the community varies 

 within wide limits, as regards both severity and 

 duration, it is impossible to lay down standards 

 which will be uniformly applicable. So far as 

 the minimum wage is concerned, there is abso- 

 lutely no difficulty. 



It may be well to state briefly, in the first place, 

 the methods by which science has reached its 

 definite conclusidns, as the whole question is de- 

 pendent on the fact that food is consumed as a 

 source of energy for internal and external work. 

 The demands for internal work are fairly definitely 

 known, and are a function of the mass of the 

 active tissue (mainly muscle) of the body. This 

 fraction will be considered under the terms of basal 

 or standard metabolism — i.e. the energy require- 

 ments when the body is in a state of complete 

 repose. In order to assess the amount of work 

 NO. 2661, VOL. 106] 



done, both internal and external, and the amount 

 of food which must be consumed in order to cover 

 this, it is obvious that there must be some com. 

 mon unit to which everything is reduced. The 

 unit most generally utilised is the large calorie, as 

 all forms of energy may finally be reduced to 

 terms of heat. The large calorie is the amount of 

 heat required to raise i kilo, of water from 15° to 

 16° C. 



The number of Calories contained in a unit mass 

 of food can be determined directly by burning the 

 food in a special small steel chamber (the bomb 

 calorimeter) where the heat liberated by the com- 

 bustion of the food material is taken up by water 

 contained in a water-jacket, the rise of the tem- 

 perature of the water being measured by a sensi- 

 tive thermometer. The amount of energy given 

 off by the body can also be determined, either 

 directly by measuring the amount of heat given 

 off as heat and estimating the external work done 

 in work units, which, in turn, can also be stated 

 in terms of heat, or indirectly by means of the 

 exact analysis of the expired air, where each litre 

 of oxygen consumed can be calculated in terms of 

 Calories. 



The cost of the internal work, the basal meta- 

 bolism, is, as already mentioned, a function of the 

 amount of active metabolic tissue present in the 

 organism. It is obvious that the actual amount 

 of such tissue cannot be directly determined in 

 the living subject. Formerly it was assumed that 

 the weight of the individual gave a good approxi- 

 mation, and that therefore the Calorie output per 

 kilogram body weight — i.e. including active tissue 

 like muscle and inactive tissue like fat — would be 

 the measure of the cost of internal work. Recent 

 research has shown that such a value is an ap- 

 proximation only ; that much more uniform values 

 can be obtained if the weight-factor is correlated 

 with the age and the height of the individual. 

 The basal metabolism by the use of suitable 

 formulae can now be stated in terms of Calories 

 per square metre surface of the body. The mean 

 of a large number of determinations has shown 

 that the basal metabolism of a man between the 

 ages of twenty and fifty on an ordinary diet is 

 39-7 Calories per square metre surface per hour. 

 It is generally accepted that the " average " man 

 has a surface of about 1-77 square metres, and, 

 therefore, a daily basal metabolism of approxi- 

 mately 1700 Calories — i.e. as cost of internal work. 



This method of assessing the basal metabolism 



