THE CHEMISTRY OF COFFEE AXD TEA. 359 



trated between the surrounding strata, often to enormous distances. 

 The hard crystalline materials and dikes remain now as mountains ; 

 the remnants of lava-streams stand as isolated plateaus ; while the softer 

 materials have been carried away. The matters ejected from vol- 

 canoes are often carried by winds or currents to very great distances. 

 Pumice floats out upon the ocean, and has been found so thick near tin; 

 Lipari Islands that a boat could hardly make progress through it, and 

 so abundant near the Solomon Islands that it took ships three days to 

 force their way through the floating masses. Volcanic dust has been 

 blown all over the ocean and across it, and has been found by deep-sea 

 soundings to cover the bottom of the deepest parts and those farthest 

 from the land. 



The results of volcanic action, whether viewed singly or collectively, 

 appear immense, and seem to indicate that the earth is or has been the 

 prey to tremendous and terrible forces. Yet the action passes, and 

 probably always has passed, without inflicting any permanent disturb- 

 ance upon the condition of the earth's surface over more than the most 

 limited areas. Clear proofs exist that the volcanoes of the Hebrides, 

 of the Auvergne, and of Hungary, were clothed in Miocene times with 

 luxuriant forests. The Island of Java, near the heart of the present 

 most active volcanic center on the globe, is at the same time one of 

 the richest and most fertile spots in respect to vegetable and animal 

 life. The slopes of Vesuvius afford the best field for vineyards, and 

 are in constant demand for that purpose, notwithstanding the danger 

 of spasmodic outbreaks, for the eruptions of the volcano are short and 

 its periods of repose are long. Volcanic action is only one of the ordi- 

 nary forces of nature, probably quite as beneficial as destructive in the 

 long run. 







THE CHEMISTEY OF COFFEE AND TEA. 



By ALBEET B. PEESCOTT, 



PROFESSOR OF ORGANIC AND APPLIED CHEMISTRY IN THE UNIVERSITY OF MICHIGAN. 



THE vegetation on the southern slopes of the eastern Himalayas, 

 three or four thousand feet above the sea, though by no means 

 luxuriant, is said to be very agreeable and of much interest to the 

 botanist. Among the plants native to these slopes, planted in the 

 course of nature during the preparation of the earth for man, and left 

 wild with the elephant and the leopard, is a shrub growing from twenty 

 to thirty feet high, and well worthy to be selected for pleasant foliage 

 and fine flowers. The lanceolate leaves are from two to six inches 

 long, and the flowers are large and white, very fragrant, in clusters of 

 two or three in the axils of the leaves. This is the tea-plant, of the 

 genus Thea, very nearly allied to the genus Camellia, of which the 



