430 



NATURE 



[July 20, 19 16 



The amount of fuel (excluding liquid fuel) con- 

 sumed annually in the industrial area of the city is 

 estimated at about 17^ million tons, and includes 

 anthracite, coke, and bituminous coal, the last repre- 

 senting nearly one-half of the total. The following 

 figures are given, though, as all experimental details 

 are omitted, it is impossible to comment on the method 

 bv which they have been ascertained : — 



c Coal con- ^^^^t^t Loss in Percentage 



So"'^^ sumed, tons '""^"^P^"^ tons of total loss 



Steam locomotives ... 2,099,044 1*084 22,750 7*47 



Steam vessels «i,375 I "233 995 0-33 



High - pressure boilers 



and public buildings. 7,316,257 0-805 58,867 19-34 

 Low - pressure boilers 



and private houses... 4,154,746 0630 26,180 860 



Gas and coke plant ... 234,551 — — — 

 Metallurgical and other 



furnaces 3,696,550 5-291 195-599 64-26 



17, 58.', 523 1-808 304,391 100 00 



The author discusses the causes of imperfect com- 

 bustion and the best means of ameliorating the out- 

 put of smoke; but as these are generally well known 

 and recognised, at least in theory, they need not be 

 reproduced. That smoke abatement is nearly always 

 an indirect means of effecting economy is another 

 well-established fact to which he refers. Dr. Goss 

 points out the interesting observation, which may 

 not be generally known, that the visibility or other- 

 wise of smoke has no direct relation to its content 

 of solid matter. The adoption of anthracite coal or 

 coke as fuel will serve to render the discharge less 

 visible, but will not eliminate the emission of dust or 

 fine cinder. He appears to think that the replace- 

 ment of coal by electrical energy will not reduce the 

 amount of visible smoke to any serious extent, for 

 steam raising will still be necessary. The more 

 extensive use of gaseous fuel, smoke-washing, and 

 electrical precipitation of smoke as a means of smoke 

 abatement are passed over, for some unexplained 

 reason, as not within the scope of the paper. 



The author is not very optimistic in his outlook, 

 for he considers that a revolution in practice which 

 will result in the elimination of existing sources of 

 atmospheric pollution is not to be expected "because 

 present-day knowledge is insufficient to supply the 

 necessary means, and, second, because the immediate 

 application to all sources of pollution, even of such 

 means as are now available, is mechanically and 

 financially impracticable." 



If by this statement Dr. Goss includes all forms 

 of atmospheric pollution such as arise from gaseous 

 impurities and dust particles blown into the air from 

 the streets, etc., no doubt he is right; but he has him- 

 self shown that gaseous impurities are minimal in 

 quantity, because they are rapidly dispersed, whilst 

 dust particles, which exist everywhere, have never 

 been regarded as causing injury either to animal or 

 plant life. 



But the really harmful constituents of a town atmo- 

 sphere are unequivocally derived from one source — 

 the incomplete combustion of coal, and there are few 

 people who have studied the question in this country 

 who are not thoroughly convinced that the pressure 

 of properly instructed and firm control, supported by 

 adequate legal penalties and the force of intelligent 

 public opinion, would rapidly diminish and eventually 

 eliminate an evil for which no economic or, indeed, 

 any other excuse can exist. We are throwing away 

 in a wanton and criminal fashion, without let or 

 hindrance, a valuable inheritance which should belong 

 to coming generations, and which they will never be 

 able to recover. J. B. C. 



NO. 2438, VOL. 97] 



MAN AS A MACHINE.^ 

 (i) A NUMBER of different e.Kperimental methods 

 ■^'*- for deterinining the respiratory exchange of 

 man have been employed in the past, some of which 

 are designed for long experiments and some for short, 

 and of late years it has become evident that a critical 

 examination ought to be made with the view of deter- 

 mining how far the different methods give trustworthy 

 and comparable results. A comparison of this kind 

 involves very great labour, and Dr. Carpenter is to be 

 congratulated on having undertaken the work. His 

 investigation is throughout characterised by that care- 

 ful attention to detail that we have learnt to associate 

 with the Nutrition Laboratory at Boston of the Car- 

 negie Institution. 



The experimental methods examined in detail are 

 the bed respiration calorimeter described by Benedict 

 and Carpenter, two types of the Benedict universal 

 respiration apparatus, and the apparatuses described 

 by Zuntz and Geppert (the absence of the portable 

 apparatus of Zuntz is perhaps a matter for regret), by 

 Tissot and by Douglas. In addition, there is a de- 

 scription of accessory apparatus, including the Haldane 

 gas analysis apparatus. 



The experiments were made on resting subjects 

 twelve hours or more after their last meal. In each 

 experiment two of the different forms of apparatus 

 were used either alternately or in series, the periods 

 following each other as rapidly as possible. The 

 three forms of Benedict apparatus were compared with 

 one another, and the other methods were compared 

 with the Benedict universal apparatus. Full tables of 

 results are given, and these show that there is a 

 wonderfully close agreement between the average 

 figures obtained by the different methods. 



In a critical discussion the author deals with the 

 possible sources of error, as well as with the advan- 

 tages and disadvantages of each of the methods. 



In general comparable results can be obtained with 

 all the methods investigated if care is taken, but pre- 

 ference is given to the Benedict apparatus, mainly on 

 the ground that it is possible to obtain trustworthy 

 results more quickly with it than with methods which 

 involve volumetric gas analysis. 



It would have lent additional interest to this dis- 

 cussion if a few comparative experiments could have 

 been made during muscular work, as it is possible 

 that some additional sources of error or inconvenience 

 may become apparent when the different forms of 

 apparatus are called upon to deal with a greatly 

 increased respiratory exchange. 



(2) The authors confine themselves in this publica- 

 tion to the calculation from the total respiratory ex- 

 change of the actual amount of energy liberated in the 

 human body during walking exercise, but it is their 

 intention to extend their observations in the future by 

 means of direct calorimetry. An admirable introduc- 

 tion is afforded by an account of the previous history 

 of the subject, amplified by an extensive table giving 

 a complete summary of the results of previous observa- 

 tions. 



The research has been conducted throughout in the 

 laboratory on two athletic subjects. An ingenious 

 form of "horizontal treadmill is described, on which 

 the subject walks at different paces, while the respira- 

 tory exchange is measured by means of the Benedict 

 universal apparatus, various devices being employed 

 for recording automatically the distance traversed, the 

 number of steps taken, and the height through which 

 the body Is raised at each step. 



1 (i) "A Comparison of Methods for Determinin? the Respiratory 

 Exchnnge of Man." By T. IVf. Carpenter. Pp.265. (Publicntion No. 216 

 of the Carnegie Institution of Washington.) Price 2.50 dollars. 



(a) "Energy Transformations during Horizontal Walking." I'v F. G. 

 Benedict and H. Murschhauser. Pp. 100. (Publication No. 231 of the 

 Carnegie Institution of Washington.) Price i dollar. 



