% ■ ■ ' 



the Gulf Stream when they flow toward the 

 north. The ship boys amuse themselves with 

 cutting off a part of the pectoral fins, and assert, 

 that these wings grow again ; which seems to me 

 not unlikely, from facts observed in other fami- 

 lies of fishes. 



At the time I left Paris, experiments made at 

 Jamaica, by Dr. Brodbelt*, on the air contain- 

 ed in the natatory bladder of the sword-fish ^, 

 had made some naturalists think, that under the 

 tropics, in the sea fish, this organ was filled 

 with pure oxygen gas. Full of this idea, I was 

 surprised at finding in the air-bladder of the fly- 

 ing fish only 0*04 of oxygen to 0*94 of azot and 

 0*2 of carbonic acid . The proportion of this last 

 gas, measured by the absorption of lime water in 

 graduated tubes %, appeared more constant than 

 that of the oxygen^ of which some individuals 

 yielded almost double the quantity. From the 

 curious phenomena observed by Mr. Biot, Con- 

 figliachi, and Delaroche we might suppose, 

 that the sword-fish dissected by Dr. Brodbelt 

 had inhabited the lower strata of the ocean, 



* Duncan's Ann. of Medicine, 1790, p. 398. Nicholson's 

 Journ. of Nat. Phil., 4to. ed., vol. i, p. 264. 

 f Xiphias gladius. Lin. 



t Anthracometers, curved tubes with a large ball. See 

 my Essays on the atmosphere, plate 1 (German). 



§ Mem. dArcueil, vol. i, p. 257. Ann. du Mus. t. 14, 

 p. 184—217, and 246—289. Configliachi sull' Analisi dell 



