MUSEUM OF COMPARATIVE ZOOLOGY. 91 



the products of sublimation and of galvanic segregation of the metal 

 from vapor." He defined the ash bed as a " comparatively soft scoria, or 

 rotten amygdaloid, f(^rnied by the mixture of molten trai>rock and fine 

 sandstone, which have been, as it were, melted together into a very 

 spongy kind of scoria, the aqueous vapor having rendered it remarkably 

 vesicular." * He regarded the trap as having been " poured out, at dif- 

 ferent times, through a fissure, and spread over the materials of the 

 sandstone and conglomerate at the bottom of the sea, thus producing 

 alternating beds of these rocks," while in July, 185G, he seems to have 

 regarded the trap as forming dikes in the sandstone, and combining with 

 its ingredients to form the zeolites. f Prof. L. E. lUvot t regarded the 

 traps as intersti-atified sedimentary beds metamorphosed i7i siUi. The 

 sandstone formed the upper portion of, and was conformable with, 

 the copper series ; all to the Sault St. Marie making one geological 

 horizon, including the granites and iron-bearing rocks. All were taken 

 to be of the Potsdam age. The veins were considered to have been pro- 

 duced by elevation and fracture since the deposition of the entire series, 

 and the copper deposited in the wet way. 



In 1856 a " Report on the Exploration of Lakes Superior and Huron," 

 •was presented to the Legislative Assembly of Canada by Count de 

 Rottermund. It probably proved satisfactory, as we do not learn that 

 the Assembly asked for any further information from him. In the nar- 

 rative portion we are informed : " I procured a boat with four hands 

 and proceeded to Portlock Harbour. ... I met Mr. Salter with whom 

 I returned to the Bruce Klines. There we parted our provisions and 

 separated." {I. c, p. 1.) 



He attempts a classification of the formations visited, and states that 

 " this classification demands great attention, and very minute discrimi- 

 nation, to avoid the solecism of giving names according to individual 

 fancy, not used in the scientific world. Such are the names applied to 

 formations in, Canada of Huronian, Sillery, Laurentine, Richelieu, pecu- 

 liar to the localities which they indicate, substituted for Jurassic, Car- 

 boniferous, Cambrian, Devonian, etc., which are so well classified, defined, 

 and admitted throughout the scientific world." (I. c, pp. 4, 5.) 



His theory of the origin of the copper is too lengthy for insertion ; it 

 must be read to be appreciated. The result is summed up as follows : 

 " On Lake Superior the copper, in its native state is due to the de- 



* Proc. Bost. Soc. Xat. Hist., 1855, V. 279-281; 1859, VIL 31. 



t Ibid., YI. 23, 24. 



t Annales des Mines, (5,) 1855, VII. 173-328 ; 1856, X. 364-47-i. 



