Miscellaneous. 461 



electric current was then suddenly reversed : the circulation exhi- 

 bited no alteration. The stem was then exposed to the influence of 

 each of the poles separately, from the base of the stem to the apex ; 

 still no change in the circulation was visible. After each experiment 

 all magnetic influence was suppressed, but no change in the rate of 

 the motion became evident. 



It was thus shown that the magnetic force, even when prodigious, 

 exerts no influence on the circulation of Char a. Therefore there is 

 no relation between the magnetic force and the vital force producing 

 this circulation. 



These experiments, with those of 1837, prove that the circulation 

 is caused by a vital force, which is not electrical, since electricity 

 merely acts like any other exciting cause, and which has no relation 

 to the magnetic force, since the latter has not the slightest influence 

 uj^on it. 



It must be admitted therefore that the vital force is a force sui 

 generis, of the nature, relations and mechanism of which we are to- 

 tally ignorant. 



These observations must necessarily change the opinion of those 

 who consider the vital force as something imaginary. 



At the same time it must be understood, that all the causes called 

 exciting are debilitating or sedative in their primitive or direct eff*ect, 

 and only strengthening, stimulant or tonic in their secondary or indi- 

 rect effect, by reason of the vital reaction which they occasion either 

 instantaneously or after a short interval. — Comptes Rendus, April 

 16th, 1846.— A. H. 



New species of Fossil Frogs. 



M. Dunker has found some small bones of frogs in shell and co- 

 ralline deposits of Hellern, not far from Osnabruck, which belong to 

 the tertiary epoch. H. de Meyer, who has examined them, has 

 found in them at least three new species, which may be distinguished 

 particularly by the forms of the humerus. This same bone had al- 

 ready served that able palaeontologist to establish twenty-four spe- 

 cies of frogs found at Weisenau. Not one of the humeri discovered 

 at Hellern is similar to those of these twenty-four species. The 

 other bones, such as those of the sacrum, of the fore-arm and of the 

 pelvis, appear to indicate more analogy between the species of these 

 two localities. — Leonhard und Bronn's Neues Jahrbuch, 1845, p. 798. 



Description of Fossil Foot-Prints. By Alfred T. King, M.D. 



It is now more than a year since fossil foot-prints were discovered 

 in the sandstone of the coal-measures in Westmoreland county, Penn- 

 sylvania. Since then, numerous localities have been observed, which 

 contain well- characterized impressions. Some of these are similar 

 to, and a few identical with, those which I first described, but by far 

 the greatest number are totally different from any which have here- 

 tofore been observed. 



About three miles from this town, near the summit of the first 

 anticlinal roll, west of Chesnut ridge, one of the principal axes of 



