298 Wells <& Foote — One Hundred Years of Chemistry. 



under the guidance of Professor T. B. Johnson, should be 

 mentioned. 



It has happened that comparatively few publications 

 on organic chemistry have appeared in the Journal, but 

 it may be stated that the preparation of chloroform and 

 its physiological effects were described by Guthrie (21, 

 64, 1832). Unknown to him, it had been prepared by 

 Souberain, a French chemist, the previous year, but the 

 former was the first to describe its physiological action. 

 Silliman gave a sample to Doctor Eli Ives of the Yale 

 Medical School, who used it to relieve a case of asthma. 

 This was the first use of chloroform in medical practice 

 (21, 405, 1832). Guthrie also described in the Journa] 

 (21, 284, 1832) his new process for converting potato 

 starch into glucose, a method which is essentially the 

 same as that used to-day in converting cornstarch into 

 glucose. Lawrence Smith (43, 301, 1842 et seq.), Hors- 

 ford (3, 369, 1847 et seq.), Sterry Hunt (7, 399, 1849), 

 Carey Lea (26, 379, 1858 et seq.), Remsen (5, 179, 1873 et 

 seq.), and others have contributed articles on organic 

 chemistry. 



Agricultural Chemistry. 



Until near the middle of the nineteenth century, it was 

 believed that plants, like animals, used organic matter for 

 food, and depended chiefly upon the humus of the soil 

 for their growth. This view was held even long after it 

 was known that plant leaves absorb carbon dioxide and 

 give off oxygen, and after the ashes of plants had been 

 accurately analyzed. 



This incorrect view was overthrown by the celebrated 

 German chemist, Liebig, who made many investigations 

 upon the subject, and, properly interpreting previous 

 knowledge, published a book in 1840 upon the applica- 

 tion of chemistry to agriculture and physiology in which 

 he maintained that the nutritive materials of all green 

 plants are inorganic substances, namely, carbon dioxide, 

 water, ammonia (nitrates), sulphates, phosphates, silica, 

 lime, magnesia, potash, iron, and sometimes common salt. 

 He drew the vastly important conclusion that the effective 

 fertilization of soils depends upon replenishing the 

 inorganic substances that have been exhausted by the 

 crops. 



The fundamental principles set forth by Liebig have 



