IPECACUANHA 



325 



when examined under the microscope, is found to contain abundance 

 of starch grains that are mostly compound and, in addition, acicular 

 crystals of calcium oxalate ; the wood is free from vessels. These 

 characters are useful in distinguishing ipecacuanha from certain 

 substitutes that appear from time to time, and are referred to below. 



The drug has a slight odour which to many persons is particularly 

 unpleasant ; the taste is slightly bitter. The powder is often very 

 irritating to the throat and nostrils, producing violent coughing and 

 sneezing. 



The student should observe 



(a) The closely approximated disc-like cumulations, 



(b) The thick, starchy bark, 



(c) The small, dense wood ; 



and should compare this variety with Cartagena ipecacuanha, which 

 is usually rather thicker, and in 

 which the annulations assume the 

 form of distinct, somewhat distant, 

 narrow, raised ridges. 



Microscopical Characters. Below the 

 narrow cork is a largely developed 

 cortex consisting of thin-walled paren- 

 chymatous cells most of which are filled 

 with starch, but a few contain acicular 

 calcium oxalate. The bast ring is narrow, 

 and both this and the cortex are free 

 from sclerenchymatous cells and fibres 

 and from cells containing colouring 

 matter. The wood is composed of 

 tracheids, wood fibres, and parenchyma 

 and is free from typical vessels. The tra- 

 cheids, when isolated, exhibit moderately 

 thick wrlls, and often near the 

 pointed extremities a large perforation. 



The powder is characterised by the starch grains which are either oval or 

 rounded (not over 15//,) or compound with from 2 to 5 constituent grains, by 

 the acicular calcium oxalate, by the characteristic tracheids and by the absence 

 of sclerenchymatous cells, spiral vessels (ipecacuanha stem), cells containing 

 colouring water, calcium oxalate in other than acicular crystals, and typical 

 sclerenchymatous fibres or vessels. 



Constituents. Ipecacuanha root contains three alkaloids ; two of 

 which, emetine and cephaeline, have been more closely examined, 

 whilst the third, psychotrine, which occurs in much smaller quantity, 

 awaits further investigation. These alkaloids exist in good root to 

 the extent of from 2 to 3 per cent., and are contained chiefly in the 

 bark, the wood yielding only about 1 per cent. The alkaloids 

 ipecamine and hydroipecamine have also been reported as present. 



FIG. 166. True Ipecacuanha (Psy- 

 chotria Ipecacuanha). Transverse 

 section, showing dense wood. Mag- 

 nified. (Planchon and Collin.) 



