14 INTRODUCTION. 



which will continue to be felt to the most distant 

 ages of the future. We are thus rapidly and 

 imperfectly brought to the state of the science 

 in our own day. The remarkable speculations 

 and discoveries of Dr. Prout on animal, and of 

 Baron Liebig on vegetable chemistry, and the 

 chemistry of agriculture, together with the won- 

 derful discoveries of the phenomena of the che- 

 mical rays of the sunbeam by Xiepce, Daguerre, 

 Herschel, R. Hunt, and others, may be fairly 

 taken as the most valuable additions made in 

 recent times to this department of knowledge. 



In considering the present aspect and rela- 

 tions of chemistry, we are 'struck with the ex- 

 tent of its" influence, and with the importance 

 of the position it occupies. Advancing years 

 are continually extending the one, augmenting 

 the other. Every branch of the arts now ex- 

 periences its salutary reign. While it has con- 

 tributed much to the growth of other sciences, 

 by no means directly, or in the abstract, related 

 to it, it has also added a variety of substances 

 to our present list of domestic comforts and 

 conveniences. While it has tinged the purple 

 and bleached the fine linen of the great, it has 

 endowed with equal snowiness, and an equally 

 durable, though more homely lustre, the calico 

 and coarsest fabric of the poor. Nor has it 

 been less valuable in adding to our remedies 

 for the sick. For medicine, in fact, it will pro- 

 bably in future time do more, and this by reason 

 of its intimate connexion with that art, than 

 for any other department of science. In many 

 instances .chemistry detects the disease, and 

 points with much significance to the appropriate 



