52 



sesses a characteristic acrid taste when held in the mouth for a 

 short time. Under the microscope are found larj^e, one-celled 



Figure 46 

 Fig. 46. Lobelia. (1) Unicellular hairs and (2) Pollen grains. 



hairs with thick walls from 0.3 — 0.6 m.m. in length; spiral ducts, 

 but no oxalate crystals are present. Frequently smooth ellips- 

 oidal pollen grains from 15 — SO/jl in diameter are found. The 

 elements noted are shown in Fig. 40, By means of the color and 

 taste the diagnosis of this drug is made comparatively easy. 



MAY APPLE. 



( Podopli yllus peltaium . ) 



The powder of this drug is occasionally found in condimentals 

 but is rather hard to distinguish as there are no especially charac- 

 teristic tissues that aid in the diagnosis. The drug has scarcely 

 any odor, in color is usually a light yellow or whitish, and pos- 

 sesses a bitter acrid taste. It is used occasionally as a purgative 

 or tonic, and is usually present only in small quantities. 



NUX VOMICA. 



(Strychnos Ignalic) {S. nux vomica.) 



The powdered dnig is grayish white in color but does not 

 possess any great odor; the taste is intensely and persistently 

 bitter. The epidennal cells are modified so that they resemble 

 strongly lignified hairs. No calcium oxalate crystals are found 

 in the powder. The oil cells are thick walled and finely porous. 

 If on examination the presence of this drug is suspected, a sample 

 may be treated with potassium chromate and sulphuric acid, 

 when the endosperm cells will be stained blue or violet. Occa- 

 sionally very small spherical starch grains occur, which, however, 



