702 BOTANY AND PHARMACOGNOSY. 



C. SUBSTANCES MISTAKEN FOR CALCIUM OXALATE. 



Calcium oxalate crystals have been mistaken for crystalline 

 sugar, and it should also be pointed out that some of the soluble 

 carbohydrates, as hesperidin and inulin, may be mistaken for 

 sphere-crystals of calcium oxalate, which latter are of rare occur- 

 rence. Some of the soluble carbohydrates, including inulin (Fig. 

 105) occur in sphere-crystals or irregular spherical aggregates, 

 which are more or less easily soluble in water. They are found in 

 buchu, hedeoma, inula, lappa, pyrethrum, taraxacum and triticum. 



D. DRUGS CONTAINING CALCIUM CARBONATE. 

 Cannabis indica (Fig. 284, C) and ruellia (Fig. 221). 



KEY FOR THE STUDY OF POWDERS. 

 POWDERS OF A GREENISH COLOR. 



I. Crystals of Calcium Oxalate present. 



A. Crystals in rosette aggregates. 



a. Glandular and non-glandular hairs present. 



Cystoliths of calcium carbonate i. Cannabis Indica 



Twisted non-glandular hairs 2. Eriodictyon 



Starch grains 15 to 40 /* in diameter 3. Galla 



Large multicellular glandular hairs 4. Humulus 



Numerous pollen grains S- Insect Powder 



Glandular hairs few 6. Stramonii Folia 



b. Glandular hairs wanting. 



Hairs with slight projections 7. Pilocarpus 



Characteristic stone cells 8. Tea 



c. Glandular and non-glandular hairs wanting. 



Sphere-crystals of a carbohydrate 9. Buchu 



Crystals i to 2 /* in protein grains 10. Conium 



Crystals 15 ^ 11. Castanea 



Crystals 40 to 60 (>■ 12. Chimaphila 



Outer wall of epidermal cells very thick 13. Eucalyptus 



Crystal fibers 14. Granatum 



B. In monoclinic prisms. 



a. Glandular and non-glandular hairs present. 



Crystals about 10 /i 15. Hyoscyamus 



