Investigations on Bengal jail dietaries : with some observations on the influence of dietary on the physical development and well-being of the people of Bengal / by D. McCay.

  • McCay, David, 1873-
Date:
1910
Catalogue details

Licence: Public Domain Mark

Credit: Investigations on Bengal jail dietaries : with some observations on the influence of dietary on the physical development and well-being of the people of Bengal / by D. McCay. Source: Wellcome Collection.

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    be very properly analysed the diet on which this was possible, and found it to con- tain quantities of nitrogen and carbon which (when allowance is made for difference in weight) were practically identical with Letheby’s estimate for ordinary laborr in England, and of the same value as the hard labour diet of English convicts. On the basis of this experience his three scales of diet were formulated :— No. 1 Scale.—The labour scale; is simply the Bombay House of Correc- tion scale raised or lowered proportionally to the weight of the indivi- duals to be fed. No. 2 Scale.—The light labour scale; is scale No. 1 reduced in the pro- . portion that the light labour diet of English convicts is lower than. English convict hard labour diet. No. 3 Scale-—The bare sustenance scale; is scale No. 1 reduced in the proportion that a mean between Edwin Smith and Letheby’s esti- mates for bare sustenance is lower than English convict hard labour diet. Dr. Lyon, therefore, devised his diets by working back from an analysed diet: which had proved itself sufficient for all physiological purposes, 7.e., a diet from which enough of the different proximate principles was absorbed to supply the needs of the body. The ultimate object of the present investigation is to devise diet scales in which the several ingredients are so combined that the maximum absorption is obtained with a minimum of waste—a point not taken notice of in either Lyon’s diets or any other diet scales that have been framed for Indian jails. The reason why dietaries for prisoners in India have all been worked out from the chemical analyses of the fuods in use appears to be that, from the investigations. that have been carried out in Europe and America on the percentage absorption of the proximate principles, a fairly fixed proportion of these was found to be absorbed, 7.e., above 90 per cent. in a mixed animal diet and above 85 per cent. in a so-called vegetable diet. So that, by assuming these percentages to hold good for Indian food-stuffs, the framers of the different diets estimated that between 85 and 90 per cent. of the proximate principles found by chemical analysis in the diets. would be absorbed. This we shall show is not by any means the case; and, further, _we shall give abundant evidence that the actual amount of absorption does not vary directly with the quantity of the proximate principles contained in the diet ; this at least we can strongly assert is so in the case of the most important of the proximate principles—protein. It wasa very natural assumption to make and, so- far as we know, the fallacy was not discovered until actual examination* of the excreta of prisoners on a known jail diet proved that a comparatively poor absorp- tion of protein takes place when the actual amount of protein offered in the diet is. taken into consideration. * Scientific Memoirs No. 34.—Standards of the Constituents of the Blood and Urine and the Bearing of the Metabolism of the Bengali on the Problems of Nutrition. B2