April 21, 1887] 



NATURE 



579 



centuries ago ; he maintains that all the natural sciences 

 fall into two great divisions, the descriptive or physio- 

 graphical, and the philosophical or physiological. It 

 seems scarcely necessary to point out that the term 

 physiology is now so universally restricted to the study of 

 the actions of organised beings that any attempt to make 

 it include physics and chemistry, with a large part of 

 geology and astronomy, as the author proposes, can 

 scarcely be expected to meet with much success. In 

 scientific terminology a struggle for existence is continually 

 going on, and it is hopeless to fight against the results 

 of selection : to endeavour at the present day to revive 

 the older and wider meaning of the term " physiology," 

 and to use it as a synonym for " natural philosophy " side 

 by side with the modern and more restricted sense, must 

 almost infallibly lead to confusion. Still more hopeless 

 would it be to try and abolish the use of the term in its 

 present accepted sense. 



In the third essay, on " The Chemical and Geological 

 Relations of the Atmosphere," Dr. Sterry Hunt states 

 and defends his well-known speculation concerning the 

 replacement of the carbonic dioxide which is being con- 

 tinually removed from the atmosphere by the processes of 

 kaolinisation and of coal-formation. Rejecting the too 

 obvious suggestion advanced by Stanislas Meunier and 

 others, that the equivalent of the carbonic dioxide 

 abstracted from the atmosphere by the processes in 

 question may be returned to it from subterranean sources, 

 the author insists that such supplies can only come 

 from outside the earth's atmosphere, and must be cosmical 

 in their origin. The fourth essay, following up some of the 

 ideas hinted at in the third, deals with "Celestial Chemistry 

 from the Time of Newton," and is principally occupied 

 with a discussion of the nature of interstellary matter. 



The two essays dealing with " The Origin of Crystalline 

 Rocks" and "The Genetic History of the Crystalline 

 Rocks " are devoted to a destructive criticism of various 

 theories which have been propounded to account for the 

 origin of the crystallme schists and gneisses, and the 

 attempt to supply a new one. As is well known, Dr. 

 Sterry Hunt is one of those who maintain that all rocks 

 of this class are necessarily of .-Archaean age ; unlike some 

 of his contemporaries who share the same views, how- 

 ever, he does not shrink from what he believes to be the 

 logical conclusion from these premises, and maintains 

 that the formation of such rocks must result from actions 

 of a very different kind from any now going on upon the 

 globe. According to Dr. Sterry Hunt's idea, which he 

 calls the "crenitic hypothesis," "the crystalline stratiform 

 rocks, as well as many erupted rocks, are supposed to be 

 derived from a primary superficial layer, regarded as the 

 last portion of the globe solidified in cooling from a state 

 of igneous fluidity." .'\fter the wonderful speculative 

 flights of these two essays, Dr. Sterry Hunt returns to 

 the ground of sober scientific thought in several essays 

 where ordinary chemists and geologists will not find 

 themselves altogether out of their depth. 



The solid contributions made to mineralogical science 

 by the author of these essays may perhaps warrant an 

 attempt on his part to deal with the difficult and involved 

 question of mineralogical classification. This subject he 

 has treated in his essay, " A Natural System of .Miner- 

 alogy," an elaboration of which is promised in a treatise 



on mineralogy now in preparation. Dr. Sterry Hunt 

 adopts, as might be anticipated, a purely chemical classifi- 

 cation ; but his results, which differ in many important 

 particulars from those both of Rammelsberg and 

 Tschermak, do not attract us by their simplicity, and 

 seem perhaps needlessly obscured by the adoption of 

 a very cumbrous terminology. 



The essay on " The Geological History of Serpentines " 

 is one in which all the author's peculiar originality and 

 boldness are displayed in their highest perfection. That 

 in the face of the results obtained by the study of rocks 

 with the microscope, anyone could be found to maintain 

 at the present day the aqjceous origin of many, if not all, 

 serpentines, may seem startling to those who have not 

 read the author's previous writings on the subject. The 

 dexterous gliding over difficult and dangerous places, and 

 the elaborate " figure-cutting " on a few strips of appar- 

 ently solid ice, constitute one of the most remarkable 

 displays of courage and skill ever exhibited — even by the 

 great mental athlete of Canada himself ! 



The " Taconic " rocks have formed in North America 

 the battle-ground for two rival schools of geological 

 thought, exactly comparable to that afforded by the Alps 

 to European geologists, and the Scottish Highlands to 

 those of Britain. In the ninth and eleventh essays of the 

 present volume. Dr. Sterry Hunt maintains and stoutly 

 defends his well-known views concerning the origin and 

 succession of the Archaean rocks. For him the most 

 highly foliated schists and gneisses exhibit a stratification 

 clearly due to some kind of sedimentation ; in the 

 mineralogical constitution of these rocks he finds evi- 

 dences of geological age more trustworthy even than 

 those of the organic remains in the later aqueous deposits, 

 and relying implicitly upon this kind of evidence, he has 

 evolved a universal classification for the Archjean de- 

 posits which he can apply equally to the rocks of Southern 

 Europe and of British North America. At some of these 

 results persons of less robust faith in Dr. Sterry Hunt's 

 methods can only give way to " admiration," as, for 

 example, when igneous rocks which have been demon- 

 strated to be intrusive in Secondary deposits, are boldly 

 claimed, on account of their mineral characters, as mem- 

 bers of some Archjean " system " ! 



Throughout the present volume, as in the former one, 

 Dr. Sterry Hunt keeps prominently in view his claims to 

 priority, and jealously defends the originality of many of 

 the ideas he puts forward. We cannot but think our- 

 selves that the claim to originality is one which he need 

 take the smallest care to insist upon. If no name had 

 appeared upon the title-page of this remarkable work, 

 every chemist and geologist glancing at its pages would 

 have felt assured that its author could be no other than 

 Dr. Sterry Hunt. 



OUR BOOK SHELF 



Through the Fields with Linnaus. By Mrs. Florence 

 Caddy. Two Vols. (London : Longmans, Green, and 

 Co., 1887.) 

 This enthusiastic book is the fruit of the author's visit to 

 thelandofLinnasus, and her journeys in his track. Its pur- 

 pose is to tell the story of the life and labours of Linnjeus 

 with the local colour so far as it maybe restored from con- 

 temporary and other records, and from the author's own e.x- 

 periencesof travel. We find Linnseus here presented to us 



