WATTLES AND WATTLE-BARKS. 29 



2. Hickory extract (dry) forming a blackish powder having a " burnt " 



smell. Wholly soluble, but not without heating slightly ; it 

 remained twenty-four hours in cold water without entirely dissolv- 

 ing. It yielded 41*5 per cent, of tannic acid, and 17'1 per cent, 

 of moisture, but the destruction of tannic acid must have been 

 very great, and there is no necessity to go into the manufacture of 

 dry extracts until the preparation of the easier wet extracts is on 

 a better footing. 



3. Green wattle extract (Acacia deourrens) dry. Wholly soluble in 



cold water in a short time, contains 40'5 per cent, of tannic acid, 

 and 15*7 per cent of water. 



A Queensland correspondent took Acacia harpopliylla bark (found to 

 contain 1T59 per cent, of tannic acid). He converted it into extract of 

 specific gravity 1-281, the percentage then being increased to 33*82. He 

 found that 5'S1 parts of bark were required to make one of extract. 



WATTLE GALLS. 



GALLS, of course, play an important part in tanning, particularly in European 

 countries ; but it does not appear that wattle galls are likely to be of any 

 commercial importance. On some wattles, and particularly when they are 

 growing in uncongenial surroundings, or suffering from senile decay, galls 

 are very abundant, but usually they are of irregular shape (unlike oak galls), 

 and are dark-coloured and friable after the insect has made its escape. 

 Following are analyses of two species, for reference: Acacia liner vata 

 (Illawarra, New South Wales), 8 per cent, of tannic acid, and 21 '75 per cent 

 of extract; Acacia dealbata (Braidwood district, New South Wales), 3 per 

 cent, of tannic acid, and 13*6 per cent, of extract. 



WATTLE GUM. 



THOSE interested in this subject are referred to my paper in the Pharma- 

 ceutical Journal of London for the year 1890, (Pharm. Journ. [3] xx, 

 869 and 980) entitled " The Chemi&try and Commercial Possibities of Wattle 

 Gum," in which the subject is discussed from a botanical, chemical, and 

 commercial stand point. The great bulk of the paper is based on my own 

 original researches. 



