124 Proceedings of the Royal Physical Society. 
in the case of the lower metamorphic limestone shales, the 
sand of the original sea-bottom prior to its infiltration with 
calcareous matter. The details of this highly interesting field 
of inquiry are contained in a report to the British Associa- 
tion for 1859, on the " Eesults obtained by the mechaoico- 
chemical examination of Kocks and Minerals," by Alphonse 
Gages, Curator of the Museum of Irish Industry. 
The Huttonian theory, so far as it is founded upon the 
old hypothesis of a central heat, can only be accepted as a 
bold speculation. Simple and grand in its outlines, and 
affording easy and plausible explanations of many remark- 
able and mysterious phenomena in connection with the 
physical arrangement of the earth, it was readily adopted 
by scientific votaries, and became a formidable rival to the 
Wernerian system. Whatever objections may be urged 
against philosophical speculation in the abstract, it cannot 
be denied that it supplies a stimulus and gives a direct aim 
to inquiry and investigation on the science it bears upon. 
And the progress and present position which geological 
science has attained is doubtless due in a great measure to 
the rival schools of Hutton and Werner. So rapid, indeed, 
has been the progress of geology, that it may be safely 
affirmed that there are few, if any, attached to the study of 
this department of science, who are at present either Wer- 
nerian or Huttonian in the sense w^hich, in the early period 
of this century, was comprehended under these designa- 
tions. The necessity of restraining speculation and disre- 
garding premature theories of the earth has been fully 
recognised. " The geologist has discovered the importance 
of attending to the geological relations of the modern strata, 
and the laws which influence the physical and geographical 
distribution of the present races of organised beings ; in 
order that, by proceeding from the distinct to the obscure, he 
may qualify himself for illustrating, with a greater chance of 
success, the various changes w^hich the crust of this globe 
has undergone." By this method, the discovery of facts 
that are accessible to observation, and that can be tested by 
experiment, has gone on with a rapidity which the advance 
of theory has been unable to overtake. This need not dis- 
