10G8 



THORAX. 



The temperature of the respired air is not 

 mentioned.* Goodwyn states it at 200 cubic 

 inchesf ; Kite, at 300 cubic inches:]; ; Menzies 

 at 200 ; Bostock||, corroborated by Dun- 

 glison^T, omitting the complemental volume, 

 at 2 10 cubic inches; lastly, Thackral, who takes 

 this volume as the measure of health ; ex- 

 amines some soldiers, who give the mean of 

 217 cubic inches, and some shoemakers, 

 who average 182 cubic inches ; and he re- 

 marks, " a tall young cornet threw out 295 

 cubic inches ; this was the greatest quantity 

 1 ever witnessed."** 



According to this evidence, the respective 



volumes are, 



Cub. in. 



Residual volume, from 40 to 260 



Reserve ,, ,,77 170 



Breathing 3 100 



Complemental 119 200 



Vital Capacity 100 300 



The apparent discrepancies of the breathing 

 volumes are entirely due to the want of col- 

 lateral observations ; for there is no distinction 

 between the sexes, nor age, nor stature, nor 

 weight. We have determined the vital capa- 

 city in one man as 80 cubic inches, in another 

 464 cubic inches ; therefore we might say this 

 volume varies from 80 to 460 cubic inches ; 

 but this discrepancy is cleared up, when 

 we add that the height of the former was 

 3 feet 9 inches, and his weight 4 stone 9 Ibs., 

 while the latter measured 7 feet, with a weight 

 of 22 stone ; and that if we arithmetically 

 reduce the one to the other, the vital capa- 

 city of a dwarf is within half an inch of what it 

 actually was, viz. 79'56 cubic inches by cal- 

 culation, and 80 cubic inches by direct expe- 

 riment. Collateral observations clear up the 

 experiment ; thus Kite was probably a tall 

 man, and therefore he states the vital capacity 

 as 300 cubic inches; Davy at 213 cubic 

 inches, because he was of shorter stature, 

 probably about 5 feet 7 inches ; Hales, Jurin, 

 and Goodwyn about 5 feet 8 inches. We come 

 to this conclusion, because we find this vo- 

 lume bear a strict relation to stature. There- 

 fore, probably, all the observations already 

 mentioned are correct, and only wanted an- 

 other combination to remove the apparent 

 discrepancies. 



We have especially directed our attention 

 to one of these volumes of air, the vital 

 capacity. 



VITAL CAPACITY. There are two ways 

 of measuring the permeability of the lungs, 

 or the volumes of air which they can displace, 

 viz. by measuring the actual movement or 

 mobility of the thoracic boundaries, or by 

 directly measuring the absolute cubic inches 

 of the volume of air expired. The former 

 is open to an error, but the latter is not. 



* Thomson's Anim. Chem., 1843, p. G10. et seq. 

 j- Op. Cit. p. 32. note. 

 \ Op. Cit. p. 48. 



Mayo's Outlines of Phys., p. 76. 

 || Op. Cit. p. 321, 

 If Ibid. vol. ii. p. 91. 



** Thackral on the Effects of Arts, Trades, &c. 

 upon Health, p. 21. et seq. 



If we take the movement as an index to 

 the permeability of the lungs, we obtain an 

 evidence only of movement, and not of the 

 permeability of the lungs for air, for we may 

 move the thoracic boundaries, and yet not 

 breathe. But when we measure the volume 

 of air, it is self-evident that this must be the 

 measure of both the permeability of the 

 lungs and of mobility of the thoracic bound- 

 aries, because we cannot breathe without 

 moving. The classes of persons we examined 

 were as follow : 



No. 



Sailors (Merchant Service) - - 121 



Fire Brigade of London - - - 82 

 Metropolitan Police - - - - 144 



Thames Police - - 76 



Paupers - - - - - - 129 



Mixed Class (Artisans) ... 370 

 First Battalion Grenadier Guards - - 87 

 Royal Horse Guards (Blue) - - 59 

 Chatham Recruits - - - - 185 



Woolwich Marines - 573 



Pugilists and Wrestlers - - - 24 

 Giants and Dwarfs .... 4, 



n . . f Pressmen 30 1 

 Printers -{ r , .. , r - - 73 



L Compositors 43 J 



Draymen ------ 20 



Girls 26 



Gentlemen - - - - - 97 



Diseased Cases ----- 360 



Total - - 2430 



Each individual was subjected to the fol- 

 lowing observations : 



1st. The number of cubic inches given by 

 the deepest expiration, following the deepest 

 inspiration. This was taken three times, and 

 the highest observation was noticed. 



2nd. The inspiratory power. 



3rd. The expiratory power. 



4th. Circumference of the chest over the 

 nipples. 



5th. Mobility of the chest with a tape- 

 measure. 



6th. The height. 



7th. The weight. 



8th. The pulse (sitting). 



9th. The number of ordinary respirations 

 per minute (sitting). 



10th. The age 



llth. Temperature of the air expired. 



To determine these points, we constructed 

 an air receiver, denominated " Spirometer." 

 We used a bent tube (haemadynamometer) for 

 ascertaining the respiratory power, scales and 

 stand for the height and weight, and a com- 

 mon tape-measure for measuring the mobility 

 of the chest. 



We rarely exceeded three consecutive ob- 

 servations with the spirometer, because after 

 this the volume of respired air diminishes 

 from mere fatigue. 



To measure the vital capacity volume. 

 The SPIROMKTER (fig. 704.), consists of a 

 vessel containing water, out of which a re- 

 ceiver is raised by breathing into it through a 



