﻿lx PBOCEEDIN'GS OP THE GEOLOGICAL SOCIETY. 



so in cases of metamorphism chemistry must assert her authority. 

 If the term " metamorphic " is to be used in any other sense than 

 merely as a synonym of the word " altered," it is clear that a wide 

 field of chemical research has to be cultivated before it can be justly 

 applied in a theoretical sense. 



Endeavours to unravel the mystery of general metamorphism 

 may, at first sight, appear to be a hopeless task ; and doubtless it is, 

 so far as regards the effects of a vast period of time. But by expe- 

 riments with the means within our power — that is, by heat, water, 

 and pressure, skilfully applied, under a variety of forms — we may 

 reasonably expect to acquire some just conception of the processes by 

 which mechanical detritus could have been converted into a homo- 

 geneous crystalline mass. Even as regards time, recent researches 

 have shown the contrast of the effects of the same agents when 

 brought shortly to a close and when they are prolonged for several 

 months. "We must have multiplied synthetic experiments of the 

 kind of those instituted by Sir James Hall and Gregory Watt, and 

 since conducted with so much ingenuity and perseverance by Bischof, 

 Daubree, Delesse, Sorby, and others ; we must have it proved that, 

 by the combined action of heat, water, and pressure, something re- 

 sembling gneiss, mica-slate, clay-slate, and quartzite, with their 

 accessory simple minerals, may be formed out of sedimentary ma- 

 terials. But such experiments must, unfortunately, be of a kind and 

 on a scale that very few individuals can be expected to undertake ; 

 and they are therefore fit subjects for liberal grants from public 

 bodies entrusted with funds for the promotion of science. 



I -will now pass to a very different subject — to one which may be 

 said to have been for nearly two years the great geological question 

 of the day, and which has excited no small amount of general in- 

 terest, — the discovery of 



Evidence of the early Existence of the Human Race. 



Numerous newly discovered facts, and a more attentive and un- 

 prejudiced estimate of many of a similar kind, long since recorded, 

 seem to prove indisputably that Man must have been an inhabitant 

 of this earth at a far earlier period than we had been accustomed to 

 believe him to have existed. Ever since the discovery by Dr. Falconer 

 in 1858 of implements of human workmanship associated with the 

 bones of extinct quadrupeds in the cave at Brixham in Devonshire, 

 and the subsequent communication of Mr. Prestwich to the Royal 

 Society in May 1859, of his examination of the ground where M. 

 Boucher de Perthes had discovered, in a bed of gravel, flint hatchets 

 associated with the bones of extinct quadrupeds, at St. Acheul near 

 Amiens, and at Abbeville, this question has been a topic of intense 

 geological interest. Soon after the visit of Mr. Prestwich, to whose 

 paper in the Philosophical Transactions I must refer you for ample 

 details, M. Gaudry, a French geologist, went to St. Achcul, and in 

 two communications to the Academy of Sciences of Prance, on the 

 26th of September and 3rd of October, 1859, he gives the following 

 account of his researches : — " The grevf point was not to leave the 



