436 BOTANY AND PHARMACOGNOSY. 



of potassium chlorate, evaporating the solution and adding a 

 drop of ammonia water to the residue. (See also Fig. 159.) 



Theobromine (dimethyl xanthine) also occurs in cacao (p. 

 332) and crystallizes in rhombic prisms, which are sparingly 

 soluble in water and alcohol, the solutions being slightly acid. It 

 sublimes on heating without decomposition, and forms crystalliz- 

 able salts with mineral acids, which are readily decomposed with 

 water. Theobromine on treatment with methyl iodide yields 

 caffeine. Both caffeine and theobromine are also prepared syn- 

 thetically. 



Fresh kola nuts also yield from 0.3 to 0.4 per cent, of a 

 crystalline tannin-containing substance, kolatin, which is com- 

 bined with the caffeine as kolatin-caffeine. The latter is unstable 

 and is easily decomposed on curing or drying the drug. Kolatin 

 resembles pyrocatechin in its reactions and appears to neutralize 

 the physiological action of caft'eine, and hence the dried kola nuts 

 are more active than the fresh nuts. 



The red color in dried kola seeds is due to an oxydase similar 

 to that which causes the darkening of apples when freshly cut and 

 exposed to the air. If the seeds are first heated in boiling water 

 for 30 minutes and then dried they do not darken. 



Allied Plants. The seeds of a number of other plants are 

 said to be -sometimes admixed with kola, and of these the follow- 

 ing may be mentioned : Cola Ballayi, a plant growing in the 

 Gaboon, the seeds of which contain six cotyledons and are defi- 

 cient in alkaloids. The seeds of Garcinia Cola (Fam. Guttiferse) 

 have been substituted for Cola under the name of " Stamimte 

 Cola." These seeds do not contain caffeine, but two resins which 

 seem to have a physiological effect similar to Cola. The seeds of 

 Pentadesma hutyraccum, of Sierra Leone, have also been used as 

 a substitute for Cola ; they contain a fat, having a turpentine- 

 like odor, which is used by the natives in place of butter, and 

 hence the tree is known as the " Butter or Tallow tree." 



NUX VOMICA. The dried, ripe seeds of Strychnos Nux- 

 vomica (Fam. Loganiaceas), a small tree native of the East Indies 

 and also found growing in the forests of Ceylon, on the Malabar 

 Coast and in Northern Australia. The fruit is a kind of berry 

 with from three to five seeds, which are freed from the bitter 

 pulp by washing, and dried before exportation (p. 362). 



