238 - Review of "Outlines of the 



et ostensive scire ; tales, tanquam veri scientiarum filii, no- 

 bis (si videbitur) se adjungant ; ut omissis naturae atriis, 

 quae infiniti contriverunt, aditus aliquando ad interiora pa- 

 tefiat. From Title page of Geolog. Trans. 



But though these authors thus cautiously avoid enlisting^ 

 themselves into the ranks of systenr), yet we think it is ob- 

 vious, that, so far as the origin of trap rocks is concerned, 

 they (certainly Mr. Conybeare,) lean to Huttonian views. 

 He presents us, in a note, with a succinct statement of 

 the arguments for the hypothesis, that ascribes important 

 modifications of the earth's surface to volcanic agency ; and 

 observes in the text, that "the weight of geological authori- 

 ties decidedly preponderates, at present, in favour of the 

 igneous origin of these (trap) rocks." We have already 

 observed, that the trap rocks of this country, certainly the 

 greenstones, so far as they have been examined, present 

 appearances very similar to those in Europe ; occurring in 

 the form of beds, dykes, and overlying masses: and real- 

 ly, we do not see how any man, who will candidly examine 

 all the phenomena they exhibit, can avoid the conclusion, 

 that a volcanic agency has been empoyed in their produc- 

 tion : or, at least, in their modification. The most unprac- 

 tised observer will be struck with the marks of the former 

 action of heat, which they present ; while the most acute 

 examination serves only to bring more of these marks to 

 light. The resemblance of the amygdaloidal traps to cer- 

 tain varieties of lava ; the convulsion and distortion of other 

 strata in their vicinity ; the change in other rocks in con- 

 nection with trap dykes, answering precisely to the action 

 of heat ; and the fact, that the strata, through which these 

 dykes pass, are often bent upwards, near the line of con- 

 tact, to what, but a volcanic agency, can such circumstan- 

 ces lead the mind ? 



It may here also be mentioned, that many of the ablest 

 geologists of Europe, (such as Dr. MacCulloch, Von Buch, 

 Necker, &c.) so far as they have adopted any hypothesis 

 on the subject, are disposed to impute an igneous origin to 

 granite as well as to trap rocks. Indeed, consistency seems 

 to demand such a conclusion. For although the proofs of 

 such an origin may not be so numerous in regard to gran- 

 ite as to trap, yet the most important ones are common to 

 both. Granite exists in the form of beds, veins, and irreg- 



