Correspondence — Br. L. Leigh Fermor. 47 



certain knowledge which enables me to say with a high degree of 

 certainty whether a flint has been fractured by blows or by pressure, 

 and that in consequence these views have received definite and solid 

 support. I hope Mr. Warren will agree to accept these proposals, 

 and that the result of my examination of the flints to be fractured 

 shall appear in the pages of this journal. 



J. Kjeib Moib. 



CONCEKNING LATEKITE IN GUIANA. 



Sir, — In 1911 I contributed an article to this Magazine entitled 

 " What is Laterite ? " which arose from a discussion in these pages, 

 initiated by a review of Professor J. B. Harrison's work, The Geology 

 of the Goldfields of British Guiana (1908). In this article I put 

 forward a tentative system of classification of lateritic products, by 

 which I proposed to test the use of the word laterite by certain 

 authors. Amongst the work criticized was a paper by Professor 

 Harrison entitled " The Residual Earths of British Guiana commonly 

 termed 'Laterite'", in the Geol. Mag., 1910, pp. 439-52, 488-95, 

 553-62, and also that of Du Bois entitled " Beitrag zur Kenntniss 

 der Surinamischen Laterite ", published in TschermaWs Mittheilungen, 

 1903. I drew the conclusion (loc. cit., pp. 563-4), judging from the 

 work of Harrison and Du Bois, that the term has been too widely 

 used in the Guianas. 



Last year I received from Professor Harrison a letter to which, 

 owing to the distractions of furlough and travel, I have not been 

 able, hitherto, to give the careful consideration it deserves. From 

 Professor Harrison's letter it appears that my conclusion given above 

 is too sweeping, and therefore in justice to Professor Harrison I am 

 making this communication. 



I cannot do better than quote a section of this letter: — 



' ' With reference to the various points in my published papers noticed by you 

 I may mention that I had not an opportunity of correcting the proofs, and 

 hence there are in the papers some wordings which would have been amended 

 if I had had such an opportunity ; the copies I send you have been so corrected. 

 Among them is the heading to Table I, on p. 441. 1 The object of that table is 

 to illustrate the somewhat diverse nature of sedentary soils covering areas of 

 aluminous laterite. This is clearly seen by reference to the last sentence of 

 p. 440. Unfortunately, in copying the analyses, the word ' Ironstone ' over the 

 word ' gravel ' in the fourth column of the table was omitted. 



"During 1897-1902 I analysed several specimens of 'ironstone gravels' 

 and found them to contain from 80 to as much as 95 per cent of iron and 

 aluminum hydrates, principally the former. These bring up the lateritic 

 constituents of some of these soils very materially, for instance : — 



Fe 2 3 + Al 2 3 

 Hiamaraka Hill soil 72 per cent 



Arakaka . . . . 

 Konawaruk Eoad, 12 miles 



„ 14J „ 

 Woopu . 



Issorora . . . . 

 Malali . 



56 

 33 

 55 

 72 

 65 

 62 



1 Which Professor Harrison corrects from " Analyses of Laterite Soils " to 

 Analyses of Soils on Laterite ' ' . 



