

CHEMICAL SCIENCE. 253 



no case of sudden death has been observed, as in chloroform. When death 

 is in prospect, it conies slowly, and may be foreseen for a long time in 

 advance, and its progress noted, by the state of the head and that of the 

 pupils of the eyes. The following; experiment, reported by M. Ozanam, is 

 highly interesting ; 



" I prepared a gas-bag, containing 100 litres of carbonic acid, and resolved 

 to continue the ancsthesis as long as was possible. The animal was asleep 

 at the end of three minutes, without convulsions, and so remained, extended 

 on its side. The inhalations were continued for eighty-seven minutes, and 

 then the apparatus was withdrawn. The sleep was prolonged afterwards 

 for five minutes; towards the tenth minute the legs commenced to shake; 

 at the fifteenth the animal was up again; and thus 102 minutes were used 

 in the whole experiment a length of time much beyond what the longest 

 operations would require." 



Messrs. Ferre and Ozanam have respired the gas several times if not to 

 the production of sleep, at least to feeling its first effects. They say its taste 

 is slightly pungent, and as agreeable as that of ether; it excites salivation. 

 They propose its adoption, in surgical practice, as the least dangerous 

 method, and as sufficiently efficacious. Cbrr&pooeknce of Silllman's 



INQUIRIES INTO THE QUANTITY OF AIR INSPIRED THROUGHOUT 

 THE DAY AND NIGHT, AND UNDER THE INFLUENCE OF EXER- 

 CISE, FOOD, MEDICINE, TEMPERATURE, ETC. 



A communication on the alx)ve subject, to the Royal Society, by Edward 

 Smith, M. D., contains the results of 1200 series of observations. The 

 author himself was the subject of all the investigations. He is 38 years of 

 age, 6 feet in height, healthy and strong, and with a vital capacity of the 

 lungs of 280 cubic inches. From this communication the following facts are 

 derived : 



The total quantity of air inspired in 24 hours (allowance being made for 

 intervals, amounting, altogether to 40 minutes, during which it was not 

 recorded), was 711,000 cubic inches; or an average of 29,027 cubic inches 

 per hour, and 493 - G per minute. The quantity was much less during the 

 night than during the day. There was an increase as the morning advanced, 

 and a decrease at about 8 h 30m P. M., but most suddenly at 11 P. M. Dur- 

 ing the day, the quantity increased immediately after a meal, and then sub- 

 sided before the next meal; but in every instance it rose again immediately 

 before a meal. The rate of frequency of respiration generally corresponded 

 with the quantity, but the extremes of the day and night rates AVCTC greater. 

 The period of greatest parallelism was between tea and supper. An increase 

 was occasioned by one meal only, namely, breakfast. The average depth 

 of respiration was 26'5 cubic inches, with a minimum of 18 - 1 cubic inches in 

 the night, and a maximum of 32'2 cubic inches at l h 30 m P. M. The mean 

 rate of the pulse was 76 per minute; the minimum at 3 h 30 m A. M., the 

 maximum at 8 h 45 m A. M.; the difference being more than one-third of 

 the minimum rate. 



Sleep came on in two of the series of continuous observations, and the 

 time of its occurrence was also that of the lowest quantities of air inspired. 



The amount of breathing was greater in the standing than in the sitting 

 posture, and greater sitting than lying. It was increased by riding on 

 horseback, according to the pace, also by riding in or upon an omnibus. In 



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