of the Flints of the Upper Chalk. 291 



drawn, and that had been announced as a general law of nature 

 and necessary connexion, yet the very first case in which it was 

 observed that below 40° Fahr. an increase of dimension takes 

 place would have proved the above generalization* to have been 

 an " anticipation^-' merely. 



The reader will feel the exact pertinence of the above observa- 

 tions to the subject immediately before us. The problem is — 

 The Flints of the Upper Chalk : what are the necessary con- 

 nexions of these in character, mode of formation, &c. ? and the 

 point is to explain, upon a general and universally applicable 

 principle, the presence, in all its forms, of flint. 



To this problem Mr. Bowerbank has offered a solution, namely, 

 " that the common tuberous flints, the horizontal tabular flints, 

 and those forming perpendicular or oblique veins, were all pro- 

 duced by the same agency, namely, in all cases, from sponges 

 of which those flints occupy the exact places. ^^ I deny that this 

 is a solution of the problem ; and, having the principles above 

 glanced at before my eyes, suggest at the beginning of my argu- 

 ment f that, if it can once be shown to be impossible, in any one 

 particular instance, to explain the presence of flint on this theory 

 — if flint is ever, or may be even in a single instance, found else- 

 where — the theory ceases to be an explanation of the phsenomena, 

 and becomes of no value to the philosophical inquirer ; that it is 

 proved to be not an "interpretation,^^ but an "anticipation^' 

 merely. To this Mr. Bowerbank replies J (instead of re-examining 

 my facts, and ascertaining whether they really are the exceptions 

 I allege) by saying, " This is so richly dogmatical, that one can- 

 not suppress a smile." I have shown that constant regard for 

 such " dogmas" lies at the very foundation of all scientific inves- 

 tigation. Exact science depends wholly on them; natural 

 science becomes more exact by how much such " dogmas" are 

 continually observed. Without attention to them there can be 

 no such thing as science ; all will necessarily result in mere em- 

 piricism. 



Among the numerous services rendered to science by Professor 

 Owen, none has been more important, as it seems to me, than the 

 distinction he is perpetually enforcing, both in print and in the 

 lecture-room, between analogy and homology. That distinction, 

 without attention to which comparative anatomy can be no 



* In two articles, " On the Discovery of Truth,'* and on " The Inductive 

 System of Philosophy," in the * Christian Review' (Boston, U. S., vols, iv, 

 and v., 1839 and 1840), I have endeavoured to point out the importance and 

 universal application of the principles of investigation above glanced at. 



t See this Magazine for January of the present year, pp. 3 and 10. I 

 would also refer the reader to the bottom of p. 9 and top of p. 10. 



\ Ibid, for April, p. 251. 



21* 



