X NOTES BY THE EDITOR. 







comparisomof the weights of different substances in the gaseous 

 state which fill the unit of space at the standard temperature and 

 pressure. Though the idea of atoms is excluded from this theory, 

 it is not incompatible with them ; though it may be convenient to 

 consider matter in relation to space only, we must eventually come 

 to the consideration of what Prof. Anderson calls " the unit of 

 matter." The existence of a unit of matter, whether it be re-, 

 garded as a hard, spherical particle, a centre of force, or a vortex 

 produced in a perfect ether, appears to be indispensable ; some 

 kind of molecular hypothesis seems to be necessary for the ex- 

 planation of physical phenomena, and it is difficult not to believe 

 that some connection exists between the physical and the chemi- 

 cal unit of matter. 



A few years ago the late Dr. Emmons persistently but unsuc- 

 cessfully maintained that, below the lower Silurian system in 

 northern New York and New England, there existed an extensive 

 series of fossiliferous rocks, of which the Potsdam sandstone of 

 the New York geologists was the upper member, constituting 

 what he called the " Taconic system," and which was called in 

 Europe by Barrande the "Primordial Fauna." This view he 

 bravely maintained in opposition to all the best geologists of the 

 land. The history of this contest reminds one of that between 

 Cuvier and Geoffroy St. Hilaire in regard to the vertebral theory 

 of the skull ; the former, with great ability and brilliancy, denying 

 and ridiculing this German idea ; the latter, with truth and phi- 

 losophy, as stoutly maintaining it. So did Dr. Emmons fight sin- 

 gle-handed against the host of geologists, content, though silenced, 

 to let the power of truth prevail in its own good time. The " ver- 

 tebral theory of the skull" is now recognized, in spite of the bitter 

 opposition of Cuvier; and the "Taconic system "of Emmons, 

 since the researches of Barrande in Bohemia and of Marcou and 

 Perry in this country, must be allowed its place in geological sci- 

 ence. 



The scientific world was startled a few months ago by the pub- 

 lication of several letters said to have passed between Sir Isaac 

 Newton and the French philosopher Pascal. 



Prof. Chasles brought before the French Academy this alleged 

 correspondence between Newton and Pascal, which, if genuine, 

 would transfer to the latter much of the glory that has been asso- 

 ciated with the name of the former. 



Prof. Hirst read a paper on the subject before the British Asso- 

 ciation at the Dundee meeting, at. the request of Prof. Chasles. 



