i?vH m n b ir sins these together - Tbe »*«H to. 
T itiC * 88 ma ? be «*»* in satinwood gum, 
ot the ■»*“« «>■>««*« 
» a r V k6 ’ a8 iD owing to its 
;:i dat T •* 8 narrow -»«*, at other times it ties the 
eg to j!™ 8 teare - The snrface is sometimes quite smooth. 
sZLZ » MOriDga 8Dd Aoocardinm, sometimes 
th T^mZ m lTr tb, r** ei hjrents ° rgroore8; 
drying- generally dne to the shrinkage in 
asorilv'lT" 8 * if * 8001 is generall y oonchoidal j the colour 
Xe y P8le yell ° W t0 »“h red; the streak nsaally 
Jr: 6 r rall7tr — ^runulucent . thesarface 
^ r hnt several are dull. Many 
spedfle ^ f ra °r Te0rr0t8te tbe Plane of polarisation. The 
he dil!TI ltj 8ample8 of the — gum varies owing to 
5Err- ° f 811 «">«* •» when 
The viacatifaT Wlthwater > bllt only some actually dissolve, 
a solution of ’a “* portant quality, is tested by making 
mining the time 8ay 10 per cent ” and deter ‘ 
stopcock of a boJS T n qDantity takeS to fl ° W throu ^ ae 
same “ .° Wnpared witb ** taken by the 
longer the tim + 1 .* 8linilar solution of gnm arabic. Th® 
^ ae time, the greater the viscosity. 
according to t ^ emicaI COn8titution > may be classified 
they contain A P ^° p0rtion3 °f urabin, cerasin, and bassorin 
soluble in water ^ f ’ rea ^ i?r a mixture of glueosides, is fully 
are the best for Jh - gUm8 COntainin £ lar £e quantities of it 
(Acacia), and oth IVe pw P°i»». The best is gum arabic 
Feronia and Ana g °°^ ^ tlm8 of this class are those of 
“erelyswelling “ is in9oinbie *” water ’ 
cherry (Cerasus) a l 18 ckaracfceris tic of the gnms of the 
’ mmd ' Dea '* >1 “ lls ~i plants. Bassorin 
