EEPORT OF CHEMICAL LABORATORY 



241 



Benga. — A Magic Powder from the Bahr-El-Ghazal 

 We are indebted to Major Bray for au interesting sample of "benga," a powder used in "Benga" ; 

 the Bahr-El-Gliazal district for divinations. Major Bray writes as follows : " It is said to be p^^^^,. 

 very valuable, and to be obtained from somewhere south of Yambios. Only big ' Sultans ' 

 can use it properly. I understand that a chicken or fowl is selected, given some of the 

 powder and tied up near a lire. If the chicken dies the omen is bad, and the war (or what- 

 ever the omen concerned) is not made ; but some of the feathers of the dead chicken are tied 

 up on a stick, or on a sort uf candlestick made of wood, split and forked, about 4 feet high, 

 and put in the road or outside a tukhl. Many of the tukhls have the sticks, apparently 

 permanently fixed, outside them. Sometimes there is a little clay pot inside the forks in 

 which there are chicken bones. The powder is said to be deadly poison." 



On examination, the powder was found to consist of a brownish-red oxiile of iron, with a 

 small amount of fine sand. It contains no organic matter and nu trace of arsenic, mercury 

 or other metallic poison. In all probability the powder was selected because of its bright 

 colour, and when a bad omen was desired poison of some sort was added to it. 



Iron Ore from the Bahr-El-Ghazal 

 In the Bahr-El-Ghazal district the natives reduce their own iron from ore which is iron ore. 

 found plentifully in that locality. The reduction is effected in small furnaces by means of Qhazai 

 charcoal. A sample of the ore brought from Wan by Col. Penton, the former P.M.O., had 

 the following composition : — 



Jloisture aud small amount of organic matter ... ... ... 15'4'2 per cent. 



Sand, etc.. insol. in acid ... ... ... ... ... ... ... 28'24 „ „ 



Ferric oxide 53-20 „ „ 



Equiv. to metallic iron ... ... ... ... ... ... ... 37"24 ,, „ 



The iron reduced from this ore is said to be of excellent quality. 



Nyam Nyam Arrow Poison 



The coating of arrows with poison is common among the Nyam Nyams. A fairly large Nyam Nyam 

 quantity scraped from some arrows furnished by Captain Bethell was dissolved in water and 

 injected by Dr. Balfour into a rabbit, but \vithout effect of any kind. However poisonous 

 the material had been originally, it had evidently become inert by age. Later it was learned 

 .•that the natives recognize this fact and re-coat their arrows before each engagement. 



The substance scraped from the arrows was to a large extent soluble in water. Some 

 resin-like residue was left which gave reactions recalling those of euphorbia resin, with which, 

 however, it did not appear to be identical. Euphorbia is much used in some parts of Africa 

 as an arrow poison. 



As the poison originally present had become inert, it was not thought advisable to carry 

 the investigation further on this sample. 



Laboratory Notes 



A New and More Accurate Form of Hydrometer 

 In measuring the specific gravity of a liquid by means of the ordinary form of 

 hydrometer it is difficult to make a rigidly accurate reading. The point which should be 

 read is that at which the surface of the liquid intersects the stem of the hydrometer. In the 

 case of opaque or semi-opaque liquids, e.g., milk, this point is not visible, as the li(]uid is 

 drawn up the stem by capillary attraction. Even in tlie case of transparent liquids, the 



arrow poison 



New form of 

 Hydrometer 



