362 NATURAL SCIENCE. June, 



work, he has succeeded in transforming what tends to be a per- 

 functory restatement of the obvious into a living account of the 

 progress of science. Into the medical details, into the advances made 

 in the treatment of disease, we do not propose to enter ; we would 

 merely point out a curious recurrence to the position of Harvey. The 

 advance of science exhibits in a marked degree what Hegel called 

 the dialectic of philosophy. In the history of knowledge, any two 

 successive phases appear contradictory to each other ; but the third 

 phase is the reconciliation of contradictories in a higher unit. 



When Harvey discovered the circulation of the blood, men's 

 minds were receptive of vitalistic interpretations of nature. The 

 harmonious unity of the animal body, for instance, they did not hold 

 as a theory, but accepted with a childlike faith. In the matter of the 

 varying flow of blood " ubi stimulus ibi affluxus," " increased flow goes 

 where it is wanted," seemed to them so natural and necessary, that 

 they did not inquire into the reason of it. 



When it was realised that the heart was a force-pump, and the 

 vessels a closed system communicating with it, mechanical inter- 

 pretations held the field, and with each discovery of accelerating and 

 depressing nerves the mechanical conception became stronger and 

 stronger. But now that the intrinsic nerve-supply of the system, the 

 nerves from the brain, and the controlling vaso-motor system have 

 been demonstrated, we have reached a point where the mechanical 

 conception — apparently complete — breaks down. All the strings and 

 wires of a perfect mechanism are known, but the system works, not as 

 a perfect mechanism, but as a self-regulating, vital whole. " Ubi 

 stimulus ibi affluxus " represents exactly the position of our know- 

 ledge of to-day ; and it is a statement, not an explanation. 



Geological Literature. 

 We congratulate the Geological Society on showing itself alive 

 to the needs of the time, and entering the ranks of the bibliographers. 

 We alluded some time ago to the valuable list of accessions to the 

 library, issued every year by this society, and we then pointed out the 

 special value of that list, in that it gave one the complete geological 

 contents of every journal received, which knowledge was not to be 

 obtained elsewhere in this country. The Geological Society has now 

 dropped this mode of recording, and has issued, separately from its 

 Journal, an octavo pamphlet, entitled " Geological Literature added 

 to the Geological Society's Library during the Half-year ended 

 December, 1894." I n future, therefore, the list will be concurrent 

 with the years, instead of with the sessions of the Society — a con- 

 venient change. The present instalment, which is sold at 2s., 

 contains a four-page list of abbreviations of titles of periodical litera- 

 ture, a list of all geological papers contained in the literature received, 

 arranged alphabetically under authors, and occupying thirty-four 

 pages, and a " Subject Index " of twenty pages. 



