ON SOME N.S.W. TAN-SUBSTANCES. 29 



make a thoroughly average sample by hand-picking. Of the barks 

 I have had from 7 to 14 lbs of each. From each parcel I have 

 taken a strip which appeared to me to be an average specimen. 

 Abnormal specimens, or obviously superior or inferior ones, 

 whether of barks or kinos, have therefore been rejected. The barks 

 have (prior to grinding) been cut truly horizontal into thin sections 

 with a small guillotine, in order that the samples tested may 

 contain the proper proportions of outer and inner bark. 



The quantity operated upon for quantitative purposes has been 

 5 grammes in each case. 



Qualitative Tests. — Notes. 



1 . All tests were performed in the cold unless stated to the contrary. 



2. Ammoniacal Picric Acid gives no precipitate with any of the 



extracts, but deepens the tint of the liquid in all cases. 



3. The tests show the great similarity between the extracts of the 



barks of Acacia decurrens and A. penninervis, and the kinos 

 of Eucalyp>tus amygdalina var. and E. Sieberiana var. 



4. It is often necessary to filter, and even wash, before the colours 



of precipitates can be observed. 



Acacia sentis, (F.v. M.) N.O. Leguminosse, B. Fl. ii., 360. 



Found — In all the colonies except Tasmania, (usnally in arid country) 

 Locality of the particular specimen now under examination : — 

 Ivanhoe, via Hay, N.S.W. 

 Remarks — The bark of the trunk. Diameter of Stem 3 feet from 

 ground, 6 to 8 inches. Height of tree, 8 to 10 feet (low-spreading). 

 Date of Collection, 2nd Oct. 1886. *Date of Analysis, 17th and 

 19th May, 1887. 

 Bark fissured, but not deeply so. Of a dirty grey colour. 

 Epidermis scaly, and, when removed, showing a dark brown colour 

 underneath. Bast not readily separable ; of a light-brown colour. 

 Average thickness of bark §". Yields 18-02 per cent, of extract 

 to water at 100° C. Catechu-tannic acid 6*32 per cent. 



Qualitative Tests. — (Dilute Extract) 



1. Reaction faintly acid. 



2. Equal volume of sulphuric acid (1 in 5). In the cold, yellowish 



ppt. On boiling, slight salmon ppt. 



3. Bromine water — Slight canary yellow ppt. 



4. Dilute ferric chloride — Light indigo purple colour. Ppt on 



standing. Add Ammonia — Dark brownish purple colour 

 to ppt. 



5. Baric hydrate — Dirty brown ppt. 



6. Ammonium sulphide — Dirty yellowish colour. 



* Experiments were commenced on the first date and finished on the second. 



