SCIENTIFIC KNOWLEDGE IN LARGE TOWNS. 89 



It is thus that many great inventions have been made, and that 

 many great men have raised themselves from very humble stations 

 — Arkwright, John Hunter, and Sir Humphrey Davy are striking 

 examples. Is it not reasonable to expect that such instances will be 

 multiplied, as scientific knowledge is more extensively diffused ? 

 This town contains a vast number of artisans whose superior intel- 

 ligence and activity have raised them above their fellows. Such 

 men are exactly in a situation to profit by any scientific information 

 which may be thrown in their way. Endowed by Nature with 

 quickness of apprehension, receiving fair wages, and not so fatigued 

 with their daily occupation as those occupied in the drudgeries of 

 the manufactories, they have some time, money, and talent to bestow 

 upon the cultivation of science. 



From the labours of such men as these much good may arise to 

 our town, and much evil may be warded off from its trade ; for from 

 them may originate such improvements in machinery and in the 

 economy of manufactures as shall enable us to retain that place in 

 the great markets of the world which we have so long held, but 

 from which some think we may be one day driven by foreign com- 

 petition. 



But scientific knowledge, in penetrating to the working classes, 

 must pass through that of manufacturers ; and it is to be hoped that, 

 like light traversing diaphanous bodies, it may leave some of its rays 

 behind it ; for among this class have arisen great discoverers. Two 

 elementary substances, iodine and bromine, were respectively dis- 

 covered by a manufacturer of saltpetre and a working chemist ; and 

 it was Dolland, the optician, who, finding that a lens made of one 

 kind of glass decomposed the white light that passed through it into 

 its primitive colours, the distances between each of which were 

 greater than when it passed through one made of another kind of 

 glass, formed such a combination of these different lenses that the 

 light which had been decomposed by some was recomposed by the 

 others, with only a partial loss of the refraction, by which the appa- 

 rent sizes of objects are increased. He thus succeeded in producing 

 magnifying glasses through which the light passed to the eye in a 

 state of achromatism, i. e. devoid of colour ; a circumstance which 

 Newton had supposed could never take place. The French are fully 

 alive to the advantages which must result from their manufacturers 

 receiving a scientific education. There are, in Paris, no less than 

 three public laboratories, furnished with the most costly apparatus, 

 and superintended by the first chemists of the age, which are open 

 to all those students who by their industry and good conduct have 



VOL. VIII., NO. XXIII. 13 



