■2i0 LEGUMINOS^. 



Elephantum Correa, a spiny tree, 50 to 60 feet high, of the order' of 

 Aurantiacece, common throughout India from the hot valleys of the 

 Himalaya to Ceylon, and also found in Java. There exudes from its 

 bark abundance of gum, which appears not to be collected for exporta- 

 tion per 86, but rather to be mixed indiscriminately -with other gum, as 

 that oi Acacia. 



Feronia gum sometimes forms small roundish transparent, almost 

 colourless tears, more frequently stalactitic or knobby masses, of a 

 brownish or reddish colour, more or less deep. In an authentic sample, 

 for which we are indebted to Dr. Thwaites of Ceylon, horn-shaped 

 pieces about | an inch thick and two inches long also occur. 



Dissolved in two parts of water, it affords an almost tasteless 

 mucilage, of much greater viscosity than that of gum arable made in 

 the same proportions. The solution reddens litmus, and is precipitated 

 like gum arable by alcohol, oxalate of ammonium, alkaline silicates, 

 perchloride of iron, but not by borax. Moreover, the solution of 

 Feronia gum is precipitated bj^ neutral acetate of lead or caustic 

 baryta, but not by potash. If the solution is completely precipitated 

 by neutral acetate of lead, the residual liquid will be found to contain 

 a small quantity of a different gum, identical apparently with 

 gum arable, inasmuch as it is not thrown down by acetate of 

 lead. If the lime is precipitated from the Feronia mucilage by 

 oxalate of potassium, the gum partially loses its solubility and forms a 

 turbid liquid. 



From the preceding experiments, it follows that a larger portion of 

 J^eronia gum is by no means identical with gum arable. The former, 

 when examined in a column of 50 nun. lenoth, deviates the rays of 



ith 



o ' - - "^ wiAx^ j-xgxAUj Li\j\j K,yj fill:? 'v^ ""^ O*^*^^^ M**"* 



was, we believe, the first instance of a dextrogyre gum;' Scheibler has 

 afterwards shown (1873) that there are also dextrogyre varieties amr""' 

 the African gum fromSennar. Gum arable may be combined \v 

 oxide of lead; the compound (arabate of lead) contains -SOG per cent 

 . "f. no ?: ^^^^' whereas the plumbic compound of Feronia gum, dried 

 ^n^^j^^u-^Sj^J'^^^^"^ "'"^ ^^ly 14-7G per cent, of PbO. The formula 

 (C H- 0-)^Pb + 2 (C-H^O") supposes 14-2 per cent, of oxide of lead. 



J^eronia gum repeatedly treated with fuming nitric acid produces 

 abundant crystals of mucic acid. We found our sample of the gum to 

 yield 17 per cent, of water, when dried at 110° C. It left 3o5 per cent. 

 of ash. 



CATECHU. 



Guteclm nigrum; Black Catechu, Pegu CatecJm, Catch, Terra 

 Japonica; F. Gachou, Cachou brun oil noir ; G. Cateclm- 



Botanical Origin— The trees from which this drug is manufactured 



are of two species, namely : 



l^nvl2^'"f''* ^"^''^'^ Willd. (Mimosa Catechu- L. fil, ^^^- ff,f'k 



i^oxb.2), a tree 30 to 40 feet high, with a short, not very straight truuR 



^ FUickiger, PI,,arm, Journ. x. (18G9). garJ Mimosa {Acacia) Sundra^\^^}^l 

 borne Indian botaiu.ts, as Beddome, re- Trinien, part 1 7. 



\ 



