180 Scientific Intelligence. — Zoology. 



on Basaltic or Trap rocks, which will appear in two volumes oc- 

 tavo, with numerous sections and maps. It will, from a printed 

 prospectus sent to us, be the most complete work on this very 

 interesting subject which has hitherto been presented to the 

 public. It will appear during the course of 1831. 



ZOOLOGY. 



10. On the Existence of Animalcula hi Snow. — The follow- 

 ing account was sent by Dr J. E. Mure, in a letter to Dr 

 Silliman. — When the winter had made considerable progress, 

 without much frost, there happened a heavy fall of snow. Ap- 

 prehending that I might not have an opportunity of filling my 

 house with ice, I threw in snow, perhaps enough to fill it. 

 There was afterwards severely cold weather, and I filled the re- 

 mainder with ice. About August, the waste and consumption 

 of the ice brought us down to the snow, when it was discovered 

 that a glass of water which was cooled with it, contained hun- 

 dreds of animalcules. I then examined another glass of water 

 out of the same pitcher, and, with the aid of a microscope, be- 

 fore the snow was put into it, found it perfectly clear and pure ; 

 the snow was then thrown into it, and, on solution, the water 

 again exhibited the same phenomenon, hundreds of animalcules, 

 visible to the naked eye with acute attention, and, when viewed 

 through the microscope, resembling most diminutive shrimps, 

 and wholly unlike the eels discovered in the acetous acid, were 

 seen in the full enjoyment of 'animated nature. I caused holes 

 to be dug in several parts of the mass of snow in the ice-house, 

 and to the centre of it, and, in the most unequivocal and repeated 

 experiments, had similar results ; so that my family did not again 

 venture to introduce the snow- ice into the water they drank, 

 which had been a favourite method, but used it as an external 

 refrigerant for the pitcher. These little animals may class with 

 the amphibia which have cold blood, and are generally capable, 

 in a low temperature, of a torpid state of existence. Hence 

 their icy immersion did no violence to their constitution, and 

 the possibility of their revival by heat is well sustained by ana- 

 logy ; but their generation, their parentage, and their extraor- 

 dinary transmigration, are to me subjects of profound astonish- 

 ment. 



