104 HOLLAND: GEOLOGY OF THE NEIGHBOURHOOD OF SALEM. 



Although a few of the rocks described by Lacroix can be identi- 

 fied with fair certainty in this locality, the majority of them could not 

 be found near Salem. Some of the missing varieties, however, occur 

 in the adjoining district of Coimbatore, and others occur in the 

 Salem district at considerable distances from the capital town. At 

 the time of my visit to Salem 1 was under the impression that the 

 whole of the specimens collected by Leschenault de la Tour in South 

 India were obtained during his " voyage a Karikal et a Salem ", his 

 paper describing these journeys being the only one quoted in the 

 translation of Lacroix's paper. 1 Subsequently, however, I found on 

 looking up the original papers, that Leschenault de la Tour had made 

 much more extensive tours through the South of India than the two 

 described in the paper just referred to, and that the itinerary given 

 in a subsequently published summary of his travels 3 accounted very 

 satisfactorily for many of the rocks described by Lacroix which 

 closely resemble varieties recently found in widely separated local- 

 ities in the Madras Presidency. 



The expression " neighbourhood of Salem " used by Lacroix must, 

 therefore, be given a more than usually wide meaning, and the 

 expression "Salem district " even cannot be taken to mean the now 

 well defined area controlled by a Collector and District Magistrate. 



From the translation of Leschenault de la Tour's geological 

 observations given in an appendix to this note, it will be seen that 

 he must have travelled in the Madras Presidency through the dis- 

 tricts of South Arcot, Salem, Coimbatore, Nilgiris, Tanjore, Trichi- 

 nopoly, Madura and Tinnevelli. It is not certain, of course, that 

 he obtained specimens from all these districts, but it is certain 

 that some of the rocks described by Lacroix as t( from the neigh- 

 bourhood of Salem " really came from the Coimbatore district. As 

 the districts of Falem and Coimbatore are each of the size of the 



» Kec, Geol. Surv., Ind., Vol. XXIV, p. 158, foot-note. 



2 " Relation abr^gee d'un voyage aux Indes Orientalcs". — Mem. du Mus. d'hisl. nat. t 

 Vol. IX (1822), pp. 245—274. 



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