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THE POPULAR SCIENCE MONTHLY. 



truths in which these facts find their ex- 

 planation. The rock systems in the Phila- 

 delphia neighborhood are described, together 

 with the changes which have led to the pres- 

 ent condition of things, and the accompany- 

 ing succession of life as disclosed by fossil 

 relics. " White-Marble Steps and Window- 

 facings," "Brown-stone Fronts and Jersey 

 Mud," "Philadelphia Brick and Cobble- 

 stone," are the familiar texts used by the 

 author to interpret the wonderful workings 

 of Nature in the immeasurable past, and 

 which, through long chains of causes and 

 effects, have given rise to the present order 

 of things. The work is admirably done, 

 and the studious citizens of the Quaker 

 metropolis owe their best thanks to the 

 young geologist who has performed the 

 task. It would be a good thing if we could 

 have something of the kind in New York. 



Proceedings and Transactions of the 

 RoTAL Society op Canada, 1884. Mont- 

 real : Dawson Brothers. 



This second volume, issued by the Roy- 

 al Society of Canada, comes to us with its 

 united departments of literature and science, 

 in French or English, as the language of the 

 contributor may be. Of the scientific mem- 

 oirs only need we here speak ; they are va- 

 ried and excellent. Dr. George Lawson, 

 Professor of Botany at Dalhousie College, 

 Ilalifax, Nova Scotia, gives a revision of 

 the Canadian Ranunculacca;, in confirmation 

 and extension of a monograph published in 

 1870. During fifteen years he has given 

 direction to the observation of this import- 

 ant order by botanists afield throughout the 

 wide provinces and territories of the Domin- 

 ion. Direction of this kind gives value to 

 much of what might otherwise be but dis- 

 connected observation. Dr. Lawson's mem- 

 oir, though extensive, is incomplete in cer- 

 tain groups to which he directs the attention 

 of Canadian botanists. 



Dr. T. Sterry Hunt, of Montreal, presi- 

 dent of the society, presents a review of the 

 much controverted Taconic question in geol- 

 ogy, and shows ground for believing that 

 the newest member of the great series of 

 pre-Cambrian, crystalline, stratified rocks 

 is what is called Lower Taconic, or Tacon- 

 ian, and is widely distributed over North 

 and South America, Europe, and Asia. Dr. 



Hunt has arrived at his conclusions from 

 protracted study in America and Europe. 



From the same eminent geologist we 

 have a paper on the " Origin of Crystalline 

 Rocks." He approaches the great problem 

 of the origin of such rocks as granite and 

 gneiss, and after a discussion of the Neptu- 

 nian, igneous, and the metamorphic schools, 

 rejects them all as untenable, in favor of 

 what he calls the crenitic hypothesis, and 

 claims it as a legitimate development of the 

 Neptunism of Werner. This hypothesis 

 supposes the existence of a primary Plutonic 

 stratum, the outer layer of the original aque- 

 ous globe, which, more or less modified by 

 the subsequent penetration of water, has 

 been the direct source of eruptive rocks like 

 basalt and dolerite, and at the same time 

 has furnished indirectly and by aqueous 

 solution the elements of all granitic and 

 gneissic rocks. This radical and far-reach- 

 fng hypothesis will doubtless command the 

 attention of chemists and geologists the 

 world over. 



Other papers of interest, on topics chem- 

 ical, zoological, and physical, evidence the 

 activity of original research among men of 

 science in Canada. 



The Copper-bearing Rocks of Lake Supe- 

 RioR. By Roland Duer Irving. Wash- 

 ington : Government Printing - Office. 

 Pp. 464, with Twenty-nine Plates. 



This is a paper prepared in connection 

 with the United States Geological Survey 

 under Mr. Clarence King. It aims at a gen- 

 eral exposition of the nature, structure, and 

 extent of the series of rocks in which occurs 

 the native copper of Lake Superior ; a work 

 which has never been attempted before, nor, 

 it is asserted, could it have been accom- 

 plished sooner. Much had been written on 

 different parts of the Lake Superior basin, 

 but gaps still existed in the surveys, and 

 much remained to be learned concerning 

 the nature of the crystalline rocks. These 

 obstacles have been removed by the later 

 surveys, and the gaps that still remained 

 have been filled by the personal observa- 

 tions of Mr. Irving and his aids. All the 

 information at command has been examined 

 and drawn upon and is used, and the views 

 of different authors, often conflicting, are 

 discussed in the present work. 



