904 
ee No. 8875, 
Constituents. Meche as Laer Ts 
c. per lb. ner Ib, 
SS cum GL ere es A de acre ue ya yeu elen at eis cae per centf.. 1. 44 | 0.72 
SUL Cala (SO) iterseyee cle ae ee eas eaten a perenne) ra errata er do.... 0. 88 0. 88 
HerriciOxide (hes Oz) sse oss. oes eee ene eae Seine do..-. 0. 89 0. 89 
MPT en (@ AG) neon ele ee ee am RE tee ee aes Me et doses 7.18 | 5. 06 
BETTE Tel aN) ee ie 8 Sas i reuc\erate ey are as RN dow 10. 68 | 11.30 
TEXOHEEISH A) (RGA) eerste seats Ue er oes ie pc aay Anema do. .-- 59. 84 61. 82 
SXBCEGD:, (CONT SES OD) see aa aks ein ea ee oe NCS On Renal rateae eg ag at dow... 0.48 0. 44 
hosp noriciacid’(PsO,) 2252 eos eee aoe oe oe aes ae do. ... 12. 93 13. 20 
SHUR FULTS CAG Can (SOs) eee ere yee eer eases eee dostee 4.48 5.10 
@ homie ya (Gl) ee Se ae le = reo eee ee ee ed do.... 1, 25 0. 59 
/ 100.00 |* 100.00 
The ash of coffees.* 
FOODS AND FOOD ADULTERANTS. 
0. 74 1. 34 
0. 91 0. 69 
1.16 1.77 
4. 84 4. 94 
11.35 10. 60 
62.08 63. 60 
Bee A ats 0.17 
14. 09 11.53 
4.10 4. 88 
0.73 0. 48 
* The descriptions of samples are based on the dealer’s statements. 
tNumbers given are parts in 100 of mineral matter after deduction of carbon dioxide. Oxygen 
equivalent to chlorine is not deducted. 
t Soluble in solution of sodium carbonate. 
One of the most important constituents of coffee is the alkaloid caf. 
feine. This alkaloid is identical, chemically and physiologically, with 
tha 
t present in tea and termed ‘ theine.” 
Coffee contains a much 
smaller proportion of this alkaloid than is found in tea leaves. Caf- 
feine was discovered in 1820 by Runge,' and was isolated some time 
afterwards by Pelletier,” Robiquet,? Caventon, and Garrot. This alka- 
loid is also found in the leaves of the coffee tree. 
caffeine is present asa caffetannate. 
from coffee by extraction with chloroform. 
According to Payen4 
Caffeine may readily be obtained 
The alkaloid separated in 
this way, after purification, is obtained on evaporating the solvent in 
beautiful white silky, fibrous crystals. 
Unroasted coffees contain from 
a little less than 1 per cent to approximately 2 per cent of caffeine. 
Payen reports from 3.5 to 5 per cent caffeine plus caffetannate of 
potassium, the free alkaloid amounting to .8 per cent. 
Caffeine ® melts 
at 224° to 228° C., sublimes at 187° C., is soluble in 58 parts of water 
at 20° C., in 9.5 parts of water at 100° C., in 21 parts alcohol, in 545 
parts of ether and in 9 parts of chloroform at 20° C. 
Lapean‘ the solubility of caffeine in alcohol at 15.5° C. is 1 part in 150 
of the solvent. 
According to 
® Blyth cautions the analyst against drying this alka. 
1Schweigg. Jour. Chem. Phys. 31, 308. 
2 Jour. Pharm. [2], 12, 229. 
3 Op. cit., 234. 
4Ann. chim. phys. [3] 16, 108; Jahresb. ii. d. Fortsch. d. Chem. 1849, 486. 
6 Ann. chim. phys. [3] 26, 108; Jahresb. ii. d. Fortsch. d. Chem. 1849, 486. 
6 Vierteljahreschr. pr. Pharm 16, 167. 
7Pharm. J. Trans. [3], 11, 902; Jahresb. d. Chem. 1881, 902. 
8Foods: Their composition and analysis. A. W. Blyth. 
