iv Hutton, De Luc and Kirwan 165 



At last, after an interval of some five years, De Luc 

 assailed the " Theory " in a series of letters in the Monthly 

 Review for 1790 and 1791. So far as we know, Hutton 

 published no immediate reply to these attacks. He had 

 often been urged by his friends to publish his entire work 

 on the Theory of the Earth, with all the proofs and illus- 

 trations which had been accumulating in his hands for so 

 many years. From year to year, however, he delayed the 

 task, until during the convalescence from his first severe 

 illness, he received a copy of a strenuous attack upon his 

 system and its tendencies by Eichard Kirwan, a well- 

 known Irish chemist and mineralogist of that day. 1 This 

 assailant not only misconceived and misrepresented the 

 views which he criticized, but charged their author with 

 atheistic opinions. Weakened as he was by illness, 

 Hutton, with characteristic energy, the very day after he 

 received Kirwan's paper, began the revisal of his manu- 

 script, and worked at it until he was able to send it to the 

 press. It appeared in 1795, that is, ten years after the 

 first sketch of the subject was given to the Eoyal Society 

 of Edinburgh. Besides embodying that sketch, it gave a 

 much fuller statement of his views, and an ampler presenta- 

 tion of the facts and observations on which they were 

 founded. It formed two octavo volumes. Playfair tells 

 us that a third volume, necessary for the completion of the 

 work, remained in manuscript. 2 



1 ''Examination of the Supposed Origin of Stony Substances," read to 

 the Royal Irish Academy, 3rd February 1793, and published in vol. v. of 

 their Transactions, p. 51. For a crushing exposure of Kirwan's mode 

 of attack see Play fair's Illustrations of the Huttonian Theory, 119, 

 418. 



2 A portion of this manuscript, containing six chapters (iv.-ix.), is in 



