184/.] including Notices of Sumatra, the Malay Peninsula, ty-c. GOO 



will be found, extending to the lower ranges of the Himalayas, a large 

 part of Australia, a part of Africa, &c.) has been exposed to a well 

 marked and peculiar, perhaps a unique,* igneous action. It has 

 varied in its intensity and mode of operation, hut everywhere certain 

 prevailing characters demonstrate its unity. These are both chemical 

 and mechanical, the first depending principally on the never failing 

 presence of iron, and the latter evinced by the extraordinary uniformity 

 in the shapes, ramifications and even sizes of the ranges in which the 

 rocks affected have heen raised. Whatever be the nature of the origi- 

 nal sedimentary strata, this mighty agent has impressed them with the 

 same marks, and the more powerful its grasp has been the more have 

 their native peculiarities been confounded. But between the effects of 

 this intensest force and that so weak that we barely detect its touch, 

 the degrees are almost infinite. Still the only way in which I can 

 render this slight immethodical sketch at all intelligible, will be to note 



* This I had been very slow to believe, because although there may be places where a 

 fossil fauna or flora altogether peculiar is found, it is scarcely conceivable that any pluto- 

 nic action should have an entirely local character, or that one repeated over so many 

 parts of an extensive region in Asia, should not hitherto have been observed by Geologists 

 in Europe or America. I have however, read nearly every English work on Geology with- 

 out meeting a description of any considerable development of rocks in those quarters of 

 the globe resembling our laterites, and have consequently been obliged to work out their 

 true theory with little help from books, and by dint of patient and minute observation. 

 A few months ago I was led to think that English writers were too much occupied in 

 establishing their own opinions to present a full view of those of continental Geologists, 

 and that the latter were leaving- them behind in the science of rocks of injection, reduction 

 and eruption. It appeared necessary therefore to gather their views from their own expla- 

 nations of them. In the first work which I ordered, and which I received two days ago 

 by the Overland mail, I found an allusion to a district in Europe, which has been describ- 

 ed by an eminent French Geologist, and which, if I may judge from the few lines in 

 which it is referred to, must be in many respects analogous to the lateritic tracts of the 

 Malay Peninsula, and consequently of India, &c. also. In a few months I hope to have 

 the means of ascertaining whether this is the fact, and also whether in the writings of 

 other continental Geologists any similar tracts are noticed. A few days ago Mr. Balestier, 

 put into my hands a letter which he had received from one of the gentlemen attached to 

 the recent French Embassy to China, a pupil of the celebrated chemist Dumas, in which 

 he explains the views of himself and another member of the embassy on the Geology of 

 Singapore. His theory of the origin of the laterite had occurred to me when I hist began 

 to suspect its real nature. As my observations extended and became more minute, I 

 found that such a theory only explained a small part of the phenomena, and that which I 

 have now held for about 2 years, gradually-developed itself, growing clearer and simpler 

 in proportion as it embraced wider ranges of facts.— J. R. L. 16th March, 1847. 



