42 



NA TURE 



[November 12, 1908 



the early part of decompression, and much too fast 

 towards the end. To decompress safely a man after 

 a long exposure at, e.g., 75 lb. pressure would probably 

 require eight or ten hours if the pressure were re- 

 duced at a uniform rate throughout ; by the new 

 method here described not much more than three or 

 four hours would be required. At such pressures it 

 is clear that in practice the time of exposure must 

 be reduced. 



THE DIET OF THE HINDU.' 

 /^HITTENDEN'S well-known work on diet advo- 

 ^ cates a reduction of the nitrogen intake to an 

 amount far below that in the standard Voit dietary. 

 By experiments on others and himself, he endeavoured 

 to show that a low protein diet is compatible with 

 bodily equilibrium and health. He directs attention 

 to the well-known fact that the muscular energy of 

 the body makes little or no call on the nitrogenous 

 constituents of the muscles, and urges that the 

 excretory channels, such as the kidneys, are over- 

 worked and so liable to damage when dealing with 

 the large amount of waste nitrogen which it is the 

 habit of the white races to ingest. 



The conditions which Chittenden artificially con- 

 structed for the subjects of his experiments are found 

 ready made on a large scale in the teeming millions 

 of Bengal. It is quite obvious that much more correct 

 conclusions as to the ultimate outcome of a reduction 

 of the protein intake to less than half the European 

 standard can be drawn from 

 such a huge experiment, ex- 

 tending over the lives of a 

 population, than it is possible 

 to deduce from a limited series 

 of observations on a few men 

 lasting onlv for a few months. 

 Scientific investigators there- 

 fore owe a debt of gratitude 

 to Prof. McCay for the bril- 

 liant piece of work in which 

 he has systematically and 

 statistically grappled with the 

 problem. 



He admits it is perfectly 

 true that the Bengali of vary- 

 ing castes maintains nitrogen- 

 ous equilibrium on his poor 

 vegetarian diet, and he natur- 

 ally does not dispute the dic- 

 tum that nitrogen is not the 

 source of muscular energy. 

 But his conclusion is that the 

 low nitrogen intake acts de- 

 leteriously ; the amount of 

 protein in the blood is perman- 

 ently decreased in amount, 

 and the poor pabulum provided 

 for the muscles leads to work 

 in disadvantageous circum- 

 stances, and tends to produce degenerative changes 

 in the body cells, notably in the kidnevs. Not only is 

 the output of work by the Hindu miserably small in 

 comparison with the European labourer, but he is 

 more easily fatigued, his blood-pressure is below the 

 normal, and his lack of reserve force renders him an 

 easy prey to bacterial infection and other forms of 

 disease. His body weight and measurements show the 

 native to be a puny person, exhibiting all those signs 

 usually associated with an under-fed condition. 



1 Scientific Memoirs by the OfBcers of the Medical and Sanitary Depart- 

 ments of the Government of India (No. 34). Standards of the Constituents 

 of the Urine and Blood and the bearing of the Metabolism of Bencalis on 



Even if one grants that in the normal decomposition 

 of proteins, toxic substances are formed which may 

 act injuriously upon the body, it must be remembered 

 that in health the body is provided with an efficient 

 machinery for eliminating them. It is by no means 

 certain that decomposition products, also toxic in 

 nature, are not formed from the fat and carbohydrate 

 of the diet. The large carbohydrate intake rendered 

 necessary by a diet poor in nitrogen seems to be full 

 of danger, and the extreme prevalence of diabetes in 

 its most aggravated forms among the Bengalis proves 

 conclusively that the evils due to excess of carbo- 

 hydrate are even more real than those supposed to be 

 due to excess of protein. 



The favourite argument of the vegetarian is to point 

 to the races of the east as examples of the good results 

 accomplished on a low diet. Such an argument has 

 been refuted more than once, and its fallacies have 

 been finally demonstrated by Prof. McCay's observa- 

 tions and statistics. W. D. H. 



THE SPECTR.^ OF THE M.IJOR PL.ANETS. 



AS the result of his experiments, Mr. V. M. Slipher 

 succeeded in 1907 in renderinp- some plates 

 (Seed, 2^.1) sensitive far into the red. This was done 

 by bathing them before exposure in a solution of 

 pinacyanol, pinaverdol, dicyanin, alcohol, and water. 

 With them he photosrraphed the spectra of all the 

 major planets and, for comparison pur|)Oses, that of 

 our moon. 



URANUS 



NEPTUNE 



the Problems of Ni 

 Superintende 



By Capt. D. McCay. Pp. iv+67. (Calcutta : 

 Printing, India, 1908.) Price is. id. 



NO. 2037, VOL. 79] 



The results are shown in the accompanying print, 

 made by enlarging, combining, and re-])hotographing 

 on one plate all the spectra. Three things are to be 

 observed in the spectra : — 



(i) The great number of new lines and bands dis- 

 closed. Some of these are evident in the spectra of 

 Jupiter and Saturn, but chiefly in those of Uranus anil 

 Neptune.' 



(2) A steady progression in the intensities of the 

 non-solar lines and bands as one goes outward from 

 the sun. 



(3) The intensification of the hydrogen lines F and C, 

 notably in Uranus and Neptune. 



Perci\'al Lowell. 



