BOTANIC MATERIA MEDICA. 255 
cent. of ligenous tissue, and 7 per cent. of sa- 
line matter. The seeds of the cultivated coffee 
vary in size, and the varieties are known by the 
names of the sections in which they are grown. 
The most esteemed are the Mocha and Java va- 
Tieties. Coffees are said to improve by age. 
losing in the process of time, much of their 
strength, and improving thereby in flavor. 
Roasted coffee in form of an infusion or decoc- 
tion, is so universally used as a beverage, that 
one can scarcely callit a medicament; yet itis 
highly valued as a remedy in poisoning by the 
alkaloids of opium. The ordinary table coffee is 
tonic, stimulant and nervine, also proving a 
valuable remedy in some cases of nausea, A 
strong decoction of coffee is invaluable in poi- 
soning by opium and its preparations, and 
should be freely given. The Caffein e, although 
a constituent of coffee, is obtained from the 
dried leaves of the tea plant, and guarana caf- 
feine occurs in long, silky, flexible crystals, 
This feeble alkaloid is not often prescribed. 
The dose is 5 grains or less. 
Avena, Oat, Avena Sativa,—Natural order 
Graminacee. Said to be a native of Persia, and 
now cultivated in many parts of the world as a 
food for horses and as an article of diet. The 
clum of the Oat is smooth and arises 2 or 3 feet 
high adorned with linear-lanceolate shaped 
leaves, panicle loose and nodding; spikelets, 2 
or 3 flowered—flowerets smaller than the 
glumes and naked at the base, being alternat ely 
awned; grain or seed quite long and furrowed. 
When the grains are deprived of their thin 
outer coat, they are called prepared oats, and 
