CH. xxxvii. BARON LIE BIG. 409 



Chemistry at Giessen, where he organised the first great 

 chemical laboratory, and for twenty-seven years lectured to 

 students from all parts of the world. In 1852 he accepted 

 an invitation to Munich, where he remained for the rest of 

 his life. He was the first to analyse organic substances 

 satisfactorily, by heating them in vessels with metallic oxides, 

 thus reducing them to carbon and their other elements; 

 and to show by experiments which he made with Wohler, 

 that there is chemically no sharp line of separation between 

 organic and inorganic matter, for that, however complicated 

 the components of organic substances may be, they are 

 subject to the same chemical laws as the simpler components 

 of inorganic matter. He is, however, perhaps best known 

 for his great discoveries in agricultural chemistry. This 

 subject, which was first treated by Sir H. Davy, teaches how 

 the growth of plants depends upon the chemical state of the 

 soil in which they are sown, how different crops should be 

 sown in succession in any field so as not to exhaust the soil ; 

 and what manure will best give back to the ground the 

 elements which the plants have taken out of it. Liebig also 

 traced out the changes which food undergoes in our bodies, 

 and studied which kinds turn to fat, muscle, blood, or sugar 

 in our system. In 1832 he also discovered chloroform and 

 chlorale, though these were not used for producing uncon- 

 sciousness till more than fifteen years later by Sir James 

 Simpson. 



The whole history of organic chemistry, however, is far 

 beyond us at present, though we can understand that it has 

 opened the way for a far more real knowledge of the effects 

 of drugs, of the working of poisons, of the chemical action 

 of food in the body, and of many conditions of health and 

 disease : for if the physician can know the actual chemical 

 changes produced within the body with great accuracy, he 



