RESPIRATION. 



341 



spiration about 135 ; in a state of natural 

 expiration about 118 ; and in a state of forced 

 expiration 41 .* Goodwynf, in his experiments 

 on the capacity of the lungs upon four indi- 

 viduals after a natural death, found the resi- 

 dual air in the lungs to vary from 90 to 125 

 cubic inches, giving an average of 109, and as 

 the chest, after a natural death, may be re- 

 garded as in a state of natural or ordinary 

 expiration, this result differs very little from 

 that of Davy. Allen and Pepysj, in one 

 experiment on the capacity of the lungs in a 

 middle-sized man after death, also obtained a 

 little more than 100 cubic inches of residual 

 air. Vierordt$ supposes that the residual air 

 in the lungs, after the deepest expiration, is 

 about 600 cub. cent. (36'600 Eng. cub. in.), 

 which differs but little from the estimate of 

 Davy. 



Herbst || made experiments upon 11 males, 

 between 16 and 30 years of age, with the 

 view of ascertaining the quantity of air drawn 

 into the lungs in forced inspiration. The 

 smallest quantity observed was in a Jew aged 

 22, of small .stature, and feeble muscular sys- 

 tem. He inspired between 60 and 70 Parisian 

 cubic inches (between 72-635 and 84'738 Eng. 

 cub. in.) after an ordinary expiration ; be- 

 tween 102 and 118 (123'476 and 142'844 

 Eng. cub. in.) after a strong expiration ; and 

 120 (145-266 Eng. cub. in.) after the strong- 

 est expiration. The largest quantity inspired 

 was by a young man of 25 years, of middle 

 height with a broad chest and large and 

 powerful muscles, who inspired by a forced 

 inspiration, about 169 English cubic inches, 

 without any previous voluntary expiration; 

 about 290*- after a strong expiration ; and 

 about 290i or 295 after the strongest ex- 

 piration. A young man of 23 years of age, 

 6 feet high, with broad chest and large mus- 

 cles, inspired, without any previous voluntary 

 expiration, 121 English cubic inches, and 

 280-72 after the fullest expiration. The quan- 

 tities of air drawn into the lungs in forced 

 inspiration in the other eight males, were in- 

 termediate between the highest and lowest 

 mentioned above, and the average was about 

 202 English cubic inches.^f Herbst also sa- 

 tisfied himself that the lungs of females have 

 a considerably smaller capacity for air than 

 those of males. He states that robust fe- 

 males, about the age of 30, may inspire with- 

 out a previous voluntary expiration, 72^ 

 English cubic inches, after an ordinary ex- 



* Sir H. Davy states that this capacity is most 

 probably below the medium, as his chest was nar- 

 row. 



t Op. cit. p. 26. 



j Philos. Trans, of London, 1809; 



Op. cit. p. 892. 



|| Op. cit. p. 98. 



^[ Herbst found that a boy of 15 years inspired 

 116-16 English cubic inches after a strong expira- 

 tion, and expired the same quantity after a full in- 

 spiration. Another boy of 13 years, but of the size 

 of one of 15, likewise expired 116-16, while a boy 

 of 11 years inspired without a previous expiration, 

 36*30 ; after a strong expiration he inspired 72-60 

 English cubic inches, and expired the same quantity 

 after a full inspiration. 



piration nearly 109, and after the strongest 

 expiration, from about 157 to 174 English 

 cubic inches.* Herbst had an opportunity, 

 in two of these experiments on males, of 

 ascertaining the effects of tight clothing on 

 the extent of the respiratory movements. 

 One individual who inspired 128 and another 

 116' 16 English cubic inches, without a pre- 

 vious expiration after the clothes were loos- 

 ened, could before this only inspire 96'80 

 and 60* English cubic inches, t The most 

 extensive experiments by far, made with the 

 view of ascertaining the quantity of air which 

 can be thrown out of the lungs by forced 

 expiration, after the deepest inspiration, are 

 those of Mr. Hutchinson. These experi- 

 ments were performed upon 1923 males, and 

 they were made to breathe into an instrument 

 constructed for the purpose, and which he 

 has called a spirometer.. He has inferred from 

 the data he has collected on this point, the 

 rule, that " for every inch of height (from 

 5 feet to 6) 8 additional cubic inches of air 

 at 60 Fahr. are given out by a forced ex- 

 piration ;" so that he believes that from the 

 height alone of an adult male, he can tell 

 what quantity of air he should breathe to 

 constitute him healthy, and that this method 

 may be turned to important practical appli- 

 cation in ascertaining disease of the lungs, 



* Bourgery (op. cit.) states, that in well formed 

 and healthy individuals, a man at 30 will, by a forced 

 inspiration, draw into the lungs 2'50 to 4*30 litres (or 

 152-567 to 262-416 English cubic inches), and a woman 

 from 1-10 to 2-20 litres (or 67-129 to 134-259 English 

 cubic inches), and has inferred from his experiments, 

 that at the same age the amount of forced respiration 

 of the male doubles that of the female, and this con- 

 clusion accords with the results of Mr. Thackrah 

 (The Effects of Arts, Trades, and Professions, &c., 

 on Health and Longevity, 2nd edit. p. 181, 1832), 

 who states that " extensive examination shows us 

 that, while healthy men exhale by the pulmometer 

 200 cubic inches and upwards, women rarely exceed 

 100, and often do not reach that amount." Mr. 

 Thackrah supposes that this difference is due, to a 

 considerable extent, to tight lacing by females. 



t The condition of the stomach as to fulness, 

 also affects the extent of the, respiratory muscular 

 movements. Mr. Hutchinson. says, " I have found 

 a dinner diminish the vital capacity (by which he 

 means the greatest voluntary expiration following 

 the deepest inspiration) to the extent of 12 and, 

 even 20 cubic inches." The position of the body 

 has also, according to Mr. Hutchinson (opus cit. p. 

 197), a considerable effect upon the vital capacity of 

 the chest. In experiments upon himself he found 

 that when standing he could throw out 260 cubic 

 inches ; sitting, 255 ; and when recumbent (supine), 

 230, (prone) 220, so that position effected a difference 

 of 40 cubic inches. In a fit of dyspnoea a person can 

 breathe easier in the erect or sitting than in the re- 

 cumbent posture, as the dorsal movements that 

 attend difficult respiration, are freer in the former 

 than in the latter position. 



J Journal of the Statistical Society of London, 

 vol. vii. 1844, and Medico-Chirurgical Transac- 

 tions of London, vol. xxix. p. 137. 1846. The 

 memoir in the last publication contains a more 

 extensive series of experiments than that in the 

 former. These researches would require to be still 

 farther extended upon both sexes at the various 

 periods of life, and under varied circumstances, be- 

 fore they can yield all the information on this subject 

 that is desirable. 



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