X INTRODUCTION. 



for the vague notions of the ancient physiologist clear and 

 definite ideas of some of the most compHcated processes of 

 the human economy; instructing the dyer, the iron master, 

 and the bleacher, and contributing in innumerable ways to 

 advance the commercial greatness of the British empire, and 

 to maintain the superiority of her manufactures. 



The science of Chemistry has been cultivated from the 

 most remote times, yet its histoiy for centuries might be 

 comprised in a few pages. At one time the slave of seekers 

 for gold, and of dreamers after an eUxir which might render 

 man proof against the shafts of death, its language was 

 rendered purposely obscure, so as to be unintelhgible to the 

 bulk of the people. In later times again we find it but the 

 servant of the physician, useful in compounding the drugs 

 which he employed, and exhibiting in its menial garb little of 

 that important character which it has since assumed, and which 

 leads us now to regard it as the surest interpreter of nature, 

 and one of the most powerful instruments in advancing the 

 civilization of the world. With the advance of scientific 

 knowledge which has distinguished the present time, the 

 means for diffusing it over the world have also everywhere 

 iucreased. The railway, itself a noble monument of what 

 the science of the present age has accomplished, has become 

 one of the gi'eat instruments of extending the influence of 

 her discoveries, and is destined to accomplish far greater 

 things than the famous highways along which the arts and 

 civilization of ancient Kome were carried, and will yet be 

 the means of giving light and knowledge to the remotest 

 corners of the land. 



All professions have not been equally advanced by the 

 application of scientific knowledge. Whilst some by availing 

 themselves of its assistance have been brought to the greatest 

 perfection, others have for years remained stationaiy, or 

 have only lately received any impulse towards improvement. 

 Among the occupations of men upon which science until veiy 

 lately cast but a feeble and uncertain hght, we must place 

 the cultivation of the soil. It would occupy too much time 

 to investigate all the causes of this strange state of things ; 

 It is, however, well known that the art of agriculture, the 

 most ancient as it is the most important of human occupa- 

 tions, for centuries remained almost stationary and seemingly 

 unaffected by the onward march of society. 



