90 FLINT AND ITS APPLICATIONS. 



hair-clippings of hair-cutting rooms is sold as manure, being worth from 

 Si. to 51. per ton. 



In the Animal Collection of the South Kensington Musetini there is a 

 very good display of the applications of human hair, and the successive 

 processes which it undergoes of curling, dyeing, &c. There are also two 

 muffs made of human hair — one of black and grey hair, the other of brown 

 hair. — Editor.] 



FLINT AND ITS APPLICATIONS. 



BY THOMAS D. KOCK. 



However true the proverb, that " Familiarity breeds contempt" when 

 applied to man and his puny wisdom, it certainly has no proper reference 

 to the productions of Nature. In the vast treasure-house of Creation, the 

 smallest and most common objects are unceasingly attractive, whilst even 

 the old facts relating thereto acquire fresh interest from the new light 

 which science constantly throws upon them. 



"What subject so familiar as flint 1 so almost universally met with in 

 nature, or so generally known and understood ? And yet, I may perhaps 

 be excused for presuming that not every reader of the Technologist is 

 acquainted with its history and Applications, whilst I endeavour to 

 portray, in simple language, what is at present known concerning the 

 origin and utility of this valuable product. 



Flints are deeply interesting in a geological point of view. They are 

 found principally in what is termed the chalk formation ; most usually in 

 conchoidal masses or nodules, and of very irregular shape, though some- 

 times in thin layers, or strata, disposed either vertically or horizontally in 

 the chalk. The nodules are coated externally with a calcareous or 

 argillaceous substance, and the colour of flint varies from a light grey to 

 a deep brown or black. Many and warm were the arguments and pro- 

 positions started in times " gone by " with respect to the origin of flint ; 

 its singular formation, and position in the chalk, forming the basis of such 

 theories. Now, however, from recent discovery, we have clearer light 

 upon this subject; and although it may not be safe to make any sweeping 

 assertion, it seems to be generally supposed that the flinty nodides, at any 

 rate, are organic remains of sponges, echinites, and other kindred fossils, 

 so impregnated and incrusted with silex as to lose almost all trace of 

 their original character. A Monsieur Boucher de Perthe, a French gentleman, 

 has earned some reputation in investigations of this kind ; and Mr Bower- 

 bank has, with the aid of a microscope, discovered that all flints possess 

 a fibrous tissue like that of the sponges ; which is most confirmatory 

 evidence in support of the modern theory. 



