REPTILES. 



vncrely of an ofTeous portion, are inclined backwards, and 

 brought near the vertebral column in expiration, and are 

 extended in infpiratioii. Elevators of the ribs, iiniilar to 

 thofe of man, but larger in proportion, jjroduce the latter 

 cffeft, in which they are nflided by intercollal mufcles. The 

 inufcles carrying the ribs backward::, and thus producing 

 expiration, lie within the chcft. They are fixed to the iides 

 of the vertebral column, and correfpond in number with the 

 ribs. They are narrow and flattened, forming a kind of 

 mufcular ribbons, palling from tiie vertebral column, over 

 one rib, to be fixed in the next. Other mufcular ribbons are 

 attached to the iiifide of the ribs, defcciid to be joined to- 

 gether, and then extend acrofs, ending in a thin aponeuroiis, 

 which unites the ribbons of each fide. Thefe compofe the 

 abdominal mufclcs, and comprefs the vifcera of the great 

 cavity. 



Refpiratlon, which confifts in warm-blooded animals of 

 a conltant regular iaccefiion of alternate infpirations and 

 expirations, hardly admitting even a very (liort interruption, 

 is performed in reptiles at irregular and long intervals, ad- 

 mitting of very long fufpenlion, and capable, therefore, 

 in a much greater degree than in the former clafies, of 

 modification by the will of the animal. Hence Linnaius 

 afligned a " pulmo arbitrarius," or voluntary power over 

 the refpiratory fundfion, as a dillinguilhing attribute of 

 the clafs. The difference, however, between the reptiles 

 and warm-blooded animals is in the length of time for 

 which they can do without refpiration : after a longer or 

 Ihorter interval, its renewal is equally necedary to both. 



All reptiles continue breathing conftantly as long as 

 they are awake ; and the turtles moll frequently of all. It 

 is well known that they cannot remain long under water ; 

 but are obligi d, at fliort intervals, to come to the furface 

 for a frefli fupply of air. Blumenbach obfsrved water 

 newts, when placed in a deep vellel of water, fwim up to 

 the top frequently for the piirpofe of drawing breath. 



" On the whole, however," continues Blunienbach, 

 <' reptiles cannot only go much longer without breatliing 

 than warm-blooded animals, but they can alio continue 

 unhurt m vitiated air for a much more confiderable time. . 

 " Tortoifes have been known to live more than a montli 

 with their jaws tightly tied, and their noflrils clofed with 

 fealing-wax, (Mery, in Mem. de I'Acad. des Sciences, 

 avant 1699, v. 2.) On the fame point we may mention 

 the puzzling, but fufficiently authenticated initances, of 

 toads found alive in the middle of folid trunks of trees, 

 and even in maffes of marble and other ftones. ( Sec Lui- 

 dius in Lithophylac. Britann. p. 112. Le Cat in AUion 

 du Lac, JVIelanges d'Hiitoire Naturelle, v. 3. p. 95. 

 Gentleman's Magazine, v. 26. 1756, p. 74. Guettard in 

 Mem. fur differ, part, des Sciences et Arts, v. 4. p. 615. 

 Hift. de I'Acad. des Sciences de Berlin, 1782.) There are 

 numerous citations in Haller, de Corp. Hum. Fabrica et 

 Funtfion. v. 7. p. 151, and Kaeltner, in the Preface to 

 tlie German verfion of the Stockholm Tranfaftions, v. 3. 



" Reptiles can alfobearto breathe fixed andpfilogifticated 

 air much longer than warm-blooded animals. In my ex- 

 periments at the celebrated cavern of Pyrmont, I conftantly 

 found that pigeons could hardly be reltored to life if their 

 immerfion in that bath of carbonic acid gas was protrafted 

 into the fecond minute. Frogs, however, recovered after 

 ilaying in it five, fix, feven, and even nine minutes. The 

 event of fimilar trials, made in the famous grotto del Cane, 

 near Naples, correfponds to thefe. (See NoUet, in the Mem. 

 de I'Acad. des Sciences de Paris, 1750, p. 72. Murray, 

 in the Swedilli Tranfaftions, 1775, v. 36. p. 249.) Delia 

 Torre found that a toad lived for half an hour in that grotto, 



and that a newt wa:; (fill alive, after having been immcrfed 

 in this pernicious atmofphere an hour and a quarter. 



" Carminati has already Ihewn how much iooner confined 

 air proves fatal to warm-bhioded animals, than to the am- 

 pliibia. (Deanimalium ex inephitibus et noxiis halitibm 

 iriteritu, p. 96.) When I have enclofed two fparrows under 

 one bell-glafs, and two frogs under another of the fame fize, 

 the former have periflied in convulfions from the vitiated 

 Hate of their air, while the atmofphere of the otiier giafs 

 had experienced fo little change, that a candle or burning 

 coals were not extingniflied by it." Specimen, p. i. 



The experiments of Boyle ( Philof. Traiif. 1670, N" 62.), 

 and the Florentine academicians, which have been fince 

 moR frequently repeated, have fliewn that ferpents, frogs, 

 S:e. can remain very long (from two or three to ten or 

 twelve hours) under an exhaullcd receiver. 



The nature of the changes produced in the air by tlie 

 refpiration of reptiles, has been examined by Spallanzani 

 ( Rapports de I'air avec les ctres organifcs, publics par Sene- 

 bicr, 3 torn. 8vo. Geneve, 1807) ; Mr. EUis (Inquiry into 

 the Changes produced on Atmofpheric Air, &c. 1807, 3"d 

 Further Inquiry, &c. 181 I,) and others. The latter author 

 prefents us with a fummary of all that has been afcertaincd, 

 as well as with experiments of his own ; we, therefore, ex- 

 traft them in his own words from the works jull quoted. 



" To obtain a knowledge of the fpecific changes which the 

 air fuffers by the refpiration of the amphibia, the following 

 experiments were inllituted. A toad, Supported on a fmall 

 hoop, was inclofed in one hundred and eight cubic inches of 

 atmofpheric air contained in a jar inverted over water, and 

 ftandiiig in a room varying frum 55^ to 60^ Fahrenheit. 

 He died on the fifth day. The water had rifen confiderably 

 in the jar, and the refidual air was ilill fartlier diminifhed 

 by agitation with lime-water, which it rendered turbid. 

 Fifty parts, after being wafhed in lime-water, were next 

 fhaken in the eudiometer with the liquid lulphuret of 

 potalfa, and loil only one part of its bulk. The experiment 

 was repeated by confining another toad, in the fame manner, 

 in another jar containing forty cubic inches of atmofpheric 

 air, inverted over mercury. Under the hoop which fup- 

 ported the animal, was placed a fmall cup, containing 1.5 

 cubic inch of the water of potafla, which floated on the 

 mercury. The whole was then fet afide in a room, of the 

 temperature of 64°. By the twelfth hour, the mercury 

 had rifen nearly half an inch into the jar, which was thickly 

 moillened with vapour, and the breathing of the animal 

 feemed rather languid : by thetwenty-firft hour, he breathed 

 very faintly ; and, by the twenty-fourth hour, he had 

 ccaled to breath. The jar was allowed to ftand fome hours, 

 at the end of which time the mercury flood about eight- 

 tenths of an inch high, and one-tenth of an inch of fluid 

 was dcpefited on its furface. The jar was now raifcd, and 

 diluted fulphuric acid being poured into the alkaline folu- 

 tlon, excited m it a very brilli effervefcence. It is inferred, 

 therefore, from thefe experiments, that the oxygenous por- 

 tion of the air almoft entirely dlfappears during the refpira- 

 tion of thefe animals, after which they ceafe to breathe ; 

 and that a large portion of carbonic acid is at the fame 

 period produced. 



" Proceeding on the fuppofition, that the lofs in the bulk 

 of air, evinced by the afcent of the mercury, in the lad of 

 the foregoing experiments, arofe from the attraction of the 

 carbonic acid by the alkaline folution, we endeavoured 

 to afcertain the proportion which this lofs of bulk bore 

 to that of the whole air originally employed. With this 

 view a frog was procured, and placed in a jar of the capa- 

 city of forty cubic inches. Under the hoop which fup- 



ported 



