Intelligence and Miscellaneous Articles. 553 



must be of the greatest value. Happy may he be deemed who 

 draws from the study of geology the admirable inferences with which 

 the writer concludes, — " that past revolutions, guided by infinite 

 wisdom and beneficence, have produced a scene, not of confusion 

 but of order, and have been rendered conducive to the welfare of 

 man and of the whole animated creation." " A firm conviction," 

 he adds, " of the perfect wisdom of the scheme of creation is the 

 highest aim of science, and the chief benefit resulting from an en- 

 larged contemplation of the phenomena of nature. In order to at- 

 tain this, however, right feelings and principles, both moral and phi- 

 losophical, must be carried to the observation of the external uni- 

 verse." (P. 260.) 



LXXVII. Intelligence and Miscellaneous Articles. 



EXPERIMENTS ON COFFEE — CHLOROGENIC ACID. 



M PA YEN finds the composition of coffee to be, approximately, 

 • as follows : — 



Cellulose 34-000 



Fatty substances 10 to 13-000 



Glucose, dextrine, and an undetermined ve- "1 , r.*™ 



getable acid J 



Legumine, caseine (gluten) ? 10-000 



Chlorogenate of potash and caffeine. . . . 3-5 to 5 - 000 



Azotized organic matter 3*000 



Free caffeine 0-800 



Concrete essential oil 0*001 



Aromatic essential oil 0*001 



Mineral bodies 6-997 



Hygrometric moisture 12*000 



100-299 

 According to M. Payen the formula of caffeine is C8 H10 N2 03. 

 A part of the caffeine may be obtained directly, by treating the coffee 

 first with aether and then with absolute alcohol : by afterwards treat- 

 ing it with alcohol of - 60 several substances are separated, among 

 which is a very important crystalline body, containing the remainder 

 of the caffeine in a state of combination. These crystals are formed 

 of a double salt, resulting from the combination of an organic acid 

 (chlorogenic acid) with two bases ; one of which is organic, and is 

 caffeine ; the other mineral, is potash. 



This natural salt of coffee is then a double chlorogenate of potash 

 and caffeine : if it be rubbed after being dried at 212° on a sheet of 

 paper while hot, it is so electrical as to adhere to the blade of a knife 

 presented to it, and remains attached to it in bulky elongated floc- 

 culi. When exposed to heat it suffers no alteration from 212° F. 

 up to about 300°; but when heated to about 365° F. it fuses, be- 

 comes of a fine yellow colour, boils and swells to five times its ori- 

 ginal volume, and it remains spongy, yellowish, solid and friable ; 

 when heated to 450° F. it becomes brownish, and is partially de- 

 PJiil. Mag. S. 3. No. 197. Snppl. Vol. 29. 2 P 



