22 



tween 250,000 and 300,000. There were about 100 to the inch in 

 each electric prism, which is less than the number counted by Mr. 

 Hunter, viz. 150 to the inch. The number of prisms in each 

 battery was about 1200, each prism measuring from one to two 

 inches in height. The interval between the plates was filled with a 

 fluid, consisting of about 90 per cent, of water, containing albu- 

 men and common salt in solution. 



On examining the contents of the stomach, it was found that, 

 during the process of the digestion of the bones, the calcareous 

 matter was removed before the gelatinous matter was dissolved, 

 and Dr. Wyman had noticed the same result in the dissection of 

 other fishes. This is the reverse of what occurs in dogs and 

 hyenas, where the gelatinous matter alone is removed, the calca- 

 reous matter not being dissolved. The stomach of the specimen 

 had been acted upon by the gastric fluid after death, and was 

 perforated in its large curvature. Hydrochloric acid was de- 

 tected in its contents. 



Prof. Rogers alluded to the analogy between this animal bat- 

 tery and the ordinary metallic battery. The nervous tissue 

 might act both as generator and conductor, generating in its 

 minute ramifications, and conducting by its larger branches. 

 The disproportionate quantity of nervous tissue would not be an 

 objection to this, as batteries are constructed in which the copper 

 plate bears but a small proportion in size to the zinc, not more 

 than one twelfth perhaps, which yet exert a powerful effect, espe- 

 cially when a hot acid is employed. 



Prof. H. D. Rogers made a communication on the Epoch 

 of the Mammoth or Elephas primigenius. 



He called attention to the interesting Palceontological bear- 

 ings of a fact, which he thinks demonstrable ; that while the 

 remains of the Fossil Elephant, or Siberian Mammoth of the 

 Eastern Continent, are imbedded in the great Drift Stratum, 

 those of the Fossil Elephant of North America are as invariably 

 above it, lying in superficial deposits of a distinctly later age. 

 It is now generally conceded, that the relics of the Mastodon 

 giganteus of North America, which do not extend beyond this 

 continent, are nowhere involved in the general or earlier drift, 



