DURATION OF MUSCULAR CONTRACTION. 415 



Of the Arms. Of the Loins. 



Kilogrammes. 1 Myriagr,ammes. 



1. Van Diemen's Land, 50-6 



2. New Holland, . - 50-8 10-2 



3. Timor, - .... 58-7 11-6 



4. French, - - 69-2 15-2 



5. English, 71-4 16-3 



The highest numbers, in the first and second divisions, were respect- 

 ively 60 and 62 ; the lowest in the fifth, 63 ; in the highest 83, for the 

 strength of the arms. In the power of the loins, the highest amongst 

 the New Hollanders was 13; the lowest of the English, 12-7. 2 



The force of muscular contraction is also largely increased by the 

 proper exercise of the muscles. Hence the utility of the ancient gym- 

 nasia. In early times, muscular energy commanded respect and admira- 

 tion. It was the safeguard of individuals and families, and the protection 

 of nations; and it was esteemed a matter of national policy to encou- 

 rage its acquisition. In modern times, the invention of gunpowder 

 having altered the system of warfare, and given to skill the superiority 

 which strength communicated in personal combats, institutions for the 

 developement of the muscular system have been abandoned, until of 

 comparatively late years. They afford us striking examples of the value 

 of muscular exertion, not only in giving energy and pliancy to the frame, 

 but as a means of preserving health. 



The mean effect of the labour of an active man, working to the 

 greatest possible advantage, and without impediment, is usually esti- 

 mated to be sufficient to raise ten pounds, ten feet in a second for ten 

 hours in a day; or to raise one hundred pounds, which is the weight of 

 twelve wine gallons of water, one foot in a second, or thirty-six thou- 

 sand feet in a day; or three millions, six hundred thousand pounds, or 

 four hundred and thirty-two thousand gallons, one foot in a day. Dr. 

 Desaguliers affirms, that the weakest men who are in health, and not 

 too fat, lift about one hundred and twenty-five pounds ; and the strong- 

 est of ordinary men four hundred pounds. Topham lifted eight hun- 

 dred. The daily work of a horse is estimated to be equal to that of 

 five or six men. 



In insects, the force of muscular contraction appears to be greater in 

 proportion to their size than in any other animals. The Lucanus cer- 

 vus or Stag Beetle has been known to gnaw a hole of an inch diameter 

 in the side of an iron canister in which it had been confined, and many 

 striking examples of a similar kind are given hereafter under the head 

 of FLYING. 



In the duration of muscular contraction we notice considerable dif- 

 ference between the voluntary and involuntary muscles; the latter being 

 much more rapid and alternating. The same remark applies to the 



1 The approximate value of a kilogramme is about two pounds avoirdupois : of a myria- 

 gramme about twenty. 



a See Quetelet, Sur THomme, &c., Paris, 1835, or English edit., by Dr. R. Knox, p. 67, Edin- 

 burgh, 1842. Prof. Forbes, of Edinburgh, in London and Edinburgh Phil. Magazine, for 

 March, 1837, p. 197; and in Dunglison's American Med. Intelligencer, for May 15, 1837, 

 p. 74; in which are detailed experiments on the weight, height, and strength of above eight 

 hundred individuals, natives of England, Scotland, Ireland, and Belgium. 



