1826.] Philosophical, Chemical, and Scientific Miscellanies. 



four toes to each foot, clawless. Two spe- 

 cies have been discovered : M. latonilis 

 (the tritoii 1. of Say) and M. tetradactylus, 

 (the Protee tetradactyle of Lacepude). 



Abranchus. — This genu--', like the former, 

 has been proposed l)y Harlan. General 

 character — destitute of branchiu' at all |)e- 

 riods of its existence ; four strong legs — five 

 toes to the posterior, four to the anterior 

 extremities ; the outer edge of tlic feet fim- 

 briated; two outer toes of tiie liind feet pal- 

 mated clawless. Tlie A. allcghaniensis is 

 the only species known. 



Fanus Biiobites. — In the cabinet of the 

 Lyceum at New York there arc some fos- 

 sils from New Jersey, and the Catskills, la- 

 belled with the name biiobites ; they were 

 at lirst sli))posed to be remains analogous 

 to tlic tril'obites, but are at jjresent referred 

 to the Productus of Sowerby. 



An instrument lias been invented and 

 used with success in France, for destroying 

 a stone in the bladder ; but as it is straight, 

 and consequently not adapted to the natu- 

 ral curve of the urethra, I\Ir. Grilhths, of 

 Bentinck Street, has been induced to turn 

 his attention to the subject, and he has con- 

 structed a small machine, by means of which 

 the calculus can be retained more firmly 

 than witli any forceps, wliile it is jjcrforated 

 by a drill whicli works in a curve, and 

 broken downi into fragments, small enough 

 to pass by the urethra, an operation, in the 

 case of a large calculus, sutticiently tedious, 

 but preferable to the dangerous one of li- 

 thotomy. 



The latitude of Greenwich, as comjuitcd 

 by Professor Bessel, from the mean of a 

 great multitude of observations of ditfercnt 

 stars, is 31° ■28'.38"-34.3-|-6' 6" being a quan- 

 tity so small that it may be neglected, 

 though it has not been precisely determined. 

 The mean error of each single observation 

 is± 0"*799. It is remarkable that this de- 

 termination of the latitude of Greenwich 

 agrees much better with Mr. Pond's former 

 computation, than with that wliichProfessor 

 Bessel has deduced from Bradley's obser- 

 vations. The former was 51° 28' 37" -95, 

 the latter 31° 28' 39" "60 ; the differences 

 being — 0"-393 and -J-l"-257. 



A meteoric stone, weighing sixteen pounds 

 seven ounces, fell at Nantgemory, in Mary- 

 land, February lOtli of last year. Over an 

 extent of about fifty miles square the ex- 

 plosion which preceded, and the whizzing 

 noise which accompanied its fall, was heard 

 by several persons ; the stone was buried in 

 the ground to the depth of twenty-two or 

 twenty-four inches. 



M. Marcethas communicated to the Socie- 

 ty of Physic and Natural History at Geneva, 

 a series of experiments instituted by him, 

 which prove, most satisfactorily, that the 

 mineral and vegetable poisons produce as 

 deletereous effects on the vegetable as on the 

 animal kingdom : tlie experiments were 

 generally performed with plants of the 

 kidney bean, phascolus vulgaris, and a com- 



67 



parison was always made witli a jilant 

 watered with spring water ; tlie conclusion 

 at whicli this eminent iiaturiili>t has arrived 

 is, tliat if jilants lie destitute of organs cor- 

 responding to the nerves of animals, they 

 are capable of being alTected by such poisons 

 as act upon the latter class, in a manner 

 analogous to that in wliich animals are 

 affected by them. 



It may be readily ascertained in a moun- 

 tainous country, that the length of a flash 

 of lightning, during storms, fiuquently ex- 

 ceeds a league. This extraordinary length, 

 and the awful sound produced by the flash, 

 induces us to admit that the quantity of 

 electricity which forms it is incoiiiparubly 

 greater than that which may be accumulated 

 in the largest electric batteries : but we 

 cannot really judge of the intensity of elec- 

 tricity a<-euiiiuhitod on our conductors, and 

 on a thunder cloud, by the length of the 

 S|)ark. The electricity is retained on our 

 conductors by tlie jiressure of the air, the 

 spark only occurs when this pressure can 

 be overcome by the electricity. On the 

 contrary, the electricity is retained on a cloud 

 only by the resistance it affords to it as a 

 non-conducting body; and equally jiresscd as 

 it is by tiiis fluid, which surrounds it on 

 all sides, it should obey the slightest at- 

 tractive or repulsive force by wliicli it is 

 affected. We may therefore conceive, that 

 as soon as tlie electricity has formed a stra- 

 tum, no matter iiow attenuated so that it 

 be continuous, the flash may occur and pass 

 through considerable distances. The in- 

 tensity of the flash will be produced by the 

 quantity of electricity contained in the im- 

 mense stratum enveloping the cloud. If 

 the stratum be not continuous, which is 

 very possible in so l>ad a conductor as a 

 cloud, or if all the electricity spread over 

 tlie space occupied by the cloud have not 

 had time to disengage itself, so as to arrive at 

 the surface of the cloud, the discharge will 

 only be partial, and then the redoubled 

 peals of thunder will be easily understood. 

 It appears, impossible to M. Gay-Lussac, 

 according to these observations, that the 

 thickness of the electric stratum can ever 

 be any thing like so great on the surface of a 

 thunder cloud as on that of a solid con- 

 ductor ; for the repulsion of its molecules 

 woidd dissipate it in the air. He perceives 

 nothing to retain it but the resistance of 

 the air as a non-conductor, and tliat resis- 

 tance can^je but very small. 



An American mineralogist has observed, 

 that globides of water and air were by no 

 means unfrequent in specimens of amethyst 

 which came under his eye ; many of these, 

 from the size of the globule or portion of 

 liquid, &c. were highly interesting, and 

 most of them were found among such as 

 had been rejected on account of being too 

 pale for good cabinet specimens. 



S. Bizio, of Venice, having obtained by 

 precipitation the colouring matter of coffee, 

 has proved by numerous experiments, 



K 2 



