266 
PHARMA COON OS Y. 
illustrating the different kinds of starch grains, cal- 
cium-oxalate crystals, plant hairs, stone cells, etc., will 
be found of assistance in this connection. 
KEY FOR THE STUDY OF POWDERS. 
Powders of a Greenish Color. 
T. Crystals of Calcium Oxalate present. 
A. Calcium-oxalate crystals rosette-shaped. 
a. Secretion and non-secretion hairs present. 
Cystoliths of calcium carbonate ... 1. Cannabis Indica 
Twisted non-secretion hairs 2. Eriodictyon 
Isodiametric stone cells 3. Galla 
Large multicellular secretion hairs 4. Humulus 
Numerous pollen grains 6. Insect Powder 
Secretion hairs few 6. Stramonii Folia 
b. Secretion hairs wanting. 
Hairs with slight projections 7. Pilocarpus 
c. Secretion and non-secretion hairs wanting. 
Sphere crystals of a carbohydrate 8. Buchu 
Calcium-oxalate crystals 1-2 y 9. Conium 
Calcium-oxalate crystals 40-60 y .... 10. Chimaphila 
Outer wall of epidermal cells very thick . 11. Eucalyptus 
Crystal fibers 11a. Granatum 
B. Calcium oxalate in monoclinic prisms. 
a. Secretion and non-secretion hairs present. 
Calcium-oxalate crystals about 10 y . .12. Hyoscyamus 
b. Only non secretion hairs present. 
Characteristic stone cells . . 13. Cardamomum (Ceylon) 
Crystal fibers 14. Hamamelis 
Fragments reddish with alkalies 15. Senna 
Non-secretion hairs few 16. Uva Ursi 
c. Secretion and non-secretion hairs wanting. 
Epidermal cells with papillae 17. Coca 
Few fragments of tissues 18. Guaiaci Resina 
Few crystal fibers and non-secretion hairs . 19. Uva Ursi 
C. Calcium oxalate in crystal fibers. 
Rosette-shaped crystals numerous . . . . 20. Granatum 
Crystal fibers few 20a. Uva Ursi 
D. Calcium oxalate in cryptocrystalline crystals. 
Non-secretion and secretion hairs . 21. Belladonnse Folia 
