French National Injiitute. 577 



has always been afcribcd to the moon, feveral methods havfe 

 been tried to determine the nature ot this inliuence. Some 

 have thought that it was exercifed by means of the phales-; 

 others have fuppofed that it depended on the rcfpcdive po- 

 lition of the moon and tlie lun; and as this pofition recurs 

 nearly the fame at the end of nineteen years, the hitler havs 

 concluded that meteors niuft alfo return aimoft the fame in 

 the conrfe of that time. C. Lamarrh, who has fuppofed 

 another influence of the moon in regard to its dc( lination, 

 iind who has endeavoin-ed to cllabliih his difcovery by feverai 

 memoirs, has alfo endeavoured to afcertain what truth there 

 may be in this periodical return of the variations of the at- 

 mofphere at the rind of nineteen years; and he has found, by 

 comparing meteorological obfervations, that this return is far 

 from being fo correct as is general] v believed. Altronomers 

 alfo know well, that the cycle of nineteeai -years is not exaii 

 M-ithin an hour and a half; an error which amounts to a 

 wliolc duy in the conrfe of 308 years, 



ZOOLOGY. 



On the Difference ivhich exijls between tlM Crocodiles of the 

 old and the new Continent. 



A prccife determination of the large fpecies of animals is 

 more important than might be imaeincd, as we have in- 

 ilances that, for want of fuch dclerniinalions, travellers have 

 placed in America feveral animals of the old continent which 

 never exifted there, fuch as the lion, ticer, panther, and 

 fome others. Thele thev confounded with other animals of 

 a different kind, though nearly related to them. The fame 

 error has occurred in regard to crocodiles, even on the part 

 of naluralifts. In order to reclify fuch millakes, C, Cuvi.er 

 has fliown, that molt authors have been entirely unac- 

 quainted with tlie ditfcrence which exifts between the croco- 

 diles of the old and the new world, or have badly under- 

 Itood them, and explained them flill worfe. 



He has proved, by an accurate defcriplion, that thefe ani- 

 mals form tvv'o I'pecies, the diltinguilhing characters of which 

 are as follow : 



J ft. The crocodi/e has an oblong muzzle, the upper jaw of 

 which has indentations on each fide to aiford a paltajie to the 

 fourth tooth in the lower; its hind feet are entirely webbed, 



2d. The caiman has an obtule muzzle; its upper jaw 

 receives the fourth tooth of the lower in a particular cavity 

 which conceals it; the hind feet are only half webbed. 



The firft of thefe fpecie« belongs to the old world, the 

 fecond to the new. The name of the latter originates from 



S 3 India, 



