February 7, 1901]' 



NATURE 



343 



those on astronomy and geology — surely this, as re- 

 gards the latter, is a "cart before horse" position. It is 

 also widely separated from biology, with which it is no 

 less closely connected. 



We turn, then, to geology, which a century ago could 

 hardly claim to be a science. We find a clear sketch of 

 the principal advances, with some particulars about those 

 who made them, and only in a very few cases are we 

 inclined to dissent. To say that the " strata are level " 

 in the mountains of Sicily [and] the Scotch Highlands 

 is doubtful, unless we are rather liberal in using the term 

 mountain, and is true of only a small portion of the latter 

 region. In speaking of the joint work of Murchison 

 and Sedgwick, the author faits to mention the Cam- 

 brian system, and thus does an injustice to the man who 

 independently and accurately established its position. 

 In regard to the Laurentian system, we think that the 

 statement " they are now more generally regarded as 

 once-stratified deposits metamorphosed by the action of 

 heat " would have been truer twenty years ago than at the 

 present time, for the majority of these rocks, we think, 

 are now more commonly considered to have had an 

 igneous origin. While we believe, with the author, that 

 uniformitarian creed must not be so enunciated as to 

 exclude a certain " slowing down," we should hesitate to 

 assert that in any known era 



"large areas were rent in twain and vast floods of lava 

 flowed over thousands of square miles of the earth's 

 surface, perhaps at a single jet ; and, for aught we know 

 to the contrary, gigantic mountains may have heaped 

 up their contorted heads in cataclysms as spasmodic as 

 even the most ardent catastrophist of the elder day of 

 geology could have imagined." 



But with a crust much thinner than it has been in later 

 geological ages, fracture would be more easy and cata- 

 strophic disturbances less intense, because more frequent. 

 At any rate, the facts of geology, so far as we can re- 

 member, do not support this statement, and Lord Kelvin, 

 who is quoted in its favour, once used the simile of the 

 last spurt of a cooling porridge pot to indicate that, 

 owing to the greater resistance of the crust, a local 

 catastrophe might be as severe in a late age as in an 

 early one. Again, we demur to the following statement — 

 if the author is speaking of any known geological age — 

 that the constituents of the early atmosphere "have 

 since been stored in . . . granite." Unless we admit it 

 to have cooled on the earth's surface, how could this rock 

 plunder the atmosphere ? But Ubi plura nitent . . . 

 paucis offendar maculis ? The author gives a clear 

 sketch of the progress of geology and palaeontology from 

 infancy to adult manhood. The principal stages of 

 growth are described, even youthful escapades, the age 

 of which is not yet ended, are sometimes chronicled. But 

 for the most part he restricts himself to those hypotheses 

 which have been able to stand the test of time and are 

 now more or less promoted to the dignity of theories. 



But the advances in terrestrial and celestial physics 

 have been even more surprising. With the spectroscope 

 to investigate and the camera to record, each being a 

 discovery of this century, sun, stars, comets and nebulas 

 are yielding up their secrets ; the existence of the ether, 

 he nature of light, the relations of the physical forces, are 

 demonstrated — nay, the genesis of worlds and of matter 

 NO. 1632, VOL. 63] 



itself are becoming themes for discussion, while immense 

 advances have been made in chemistry and meteorology. 

 The same is true of the biological sciences, which have 

 been almost revolutionised since the appearance of the 

 " Origin of Species,'' little more than forty years ago. 

 Though, as these pages prove, no one would assert that 

 the last word has been said on evolution, the process, 

 however it may be explained, is a fact, and its conse- 

 quences haVe already extended far beyond biology. 



The advance is not yet ended. In proof of that we 

 need only point to the marvels of the Rontgen and 

 Becquerel rays — discoveries of the last decade. Problems 

 enough await solution in this century, of which an excel- 

 lent summary will be found in the concluding chapter. 

 Unless some dark catastrophes await civilisation, like 

 that triumph of savage ignorance which boasted that 

 "the republic has no need of savants" many secrets of 

 nature should be discovered before the new century has 

 run its course. Matter, force, energy, life — what problems 

 these four words suggest, perhaps in part inscrutable — 

 but still, even of these our descendants should know more 

 than the wisest of our own age. 



Dr. Williams has produced an interesting book, the 

 more so because it is liberally illustrated with portraits of 

 the leaders of science. These, though unpretending, are 

 often good likenesses, the other illustrations being of a 

 more commonplace character. This volume, like White's 

 " Warfare of Science," should be a manual in every course 

 of theological instruction, because the history of the pro- 

 gress of science declares how it has been opposed, in the 

 imaginary interests of religion, by the friends of the latter. 

 In the past the geologist, the biologist, the physiologist 

 have been vituperated and denounced by ignorant cham- 

 pions of theology, whose fears and assertions time has 

 proved equally unfounded. The mistakes of their fore- 

 fathers will be a lesson of caution to coming generations ; 

 for the spirit of ecclesiasticism is not yet extinct, and our 

 successors will have to confront old foes, though perhaps 

 with new faces. T. G. Bonney. 



VAN 'T HOFF'S PHYSICAL CHEMISTRY. 

 Lectures on Theoretical and Physical Chemistry. By 

 J. H. van 't Hoff. Translated by R. A. Lehfeldt. Part 

 iii. Relation between Properties and Composition. 

 Pp. 143. (London : Edward Arnold, no date.) 

 Leqons de Chimie Physique. Par J. H. van 't Hoff. 

 Ouvrage traduit de I'allemand par M. Corvisy. Trois- 

 ieme partie. Relations entre les Proprietds et la compo- 

 sition. Pp. ii + 170. (Paris : A.Hermann, 1900.) 

 THE English and French translations of the conclud- 

 ing part of van 't Hoff^s lectures are now before us. 

 Although this part ostensibly deals with the relations 

 between properties and composition, its scope is really 

 wider than its title, for it includes the discussion of 

 colligative properties, which are not related to compo- 

 sition at all. 



The first third of the book is chiefly concerned with 

 volume, pressure and temperature relations as deduced 

 from van der Waals's equation and the critical constants. 

 As a feat of terse and lucid exposition, this section is 

 unequalled in any text-book with which the present 



