ECONOMIC PRODUCTS OF THE TISSO. 251 



brings over a more limpid liquid — a fine residuum of charcoal being left in 

 the retort. This oily liquid is subjected to stirring or agitation in a 

 wooden vessel, with about one-tenth of its bulk in sulphuric acid. Much 

 of the impurities unite with the acid, and when allowed to settle fall to the 

 bottom of the vessel. The clear liquid is then drawn off", and agitated with 

 a caustic alkali, or mixture of quicklime and chalk, allowed to settle, and 

 the clear drawn off. The resultant oil is then agitated with suphuric acid, 

 as before, and again with the alkali or chalk, allowing time after each opera- 

 tion for the impurities to settle, and the oil to become a pale yellow colour. 

 It is then put into an iron retort and distilled at a moderate heat, when 

 about one-third of the quantity comes away as naphtha. The heat is then 

 elevated, when the remainder comes over — leaving a small residuum of 

 charcoal — and is an oil nearly limpid ; one part of sperm oil mixed with 

 nine parts of it making a good oil for machinery. 



ECONOMIC PRODUCTS OF THE TISSO (BUTEA FRONDOSA). 



BY M. C. COOKE, F.S.S. 



One of the most common trees of India and Assam is the Pulas or Tisso 

 (Butea frondosa), and, although seldom attaining a very large size, almost 

 every part of it may be rendered subservient to the wants of man. When 

 in flower its appearance is highly ornamental ; and, whilst not so fragrant 

 as many others of the order to which it belongs, it vies in beauty with 

 most, and in utility with any. The wood is open, soft, and tough, but 

 small in size, and is seldom employed except for coarse furniture. The 

 liber, or inner series of the bark is tough, and is convertible into a kind of 

 coarse rope. In a country yielding so many other and superior fibrous 

 plants, it is not often thus employed. From natural fissures, or wounds in 

 the bark, issues, duriug the hot season, a most beautiful red juice, which 

 concretes into a ruby-coloured, brittle, astringent gum, analogous to gum 

 kino, for which it has been employed under the name of Palass Goond, or 

 Dak gum. It soon loses its beautiful colour upon exposure to the air, 

 when it becomes duller and blacker thau the ordinary kino of commerce. 

 "This gum, when held in the flame of a candle, swells and burns away 

 slowly, without smell or the least flame, and is ultimately reduced to a fine, 

 light, white ash. If placed in the mouth it soon dissolves, its taste being 

 strongly, but simply astringent. It is not softened by heat, but rather 

 rendered more brittle. Pure water dissolves it perfectly, and the solution 

 is of a deep clear red colour. It is in a great measure soluble in spirits, 

 but this solution is paler, and a little turbid. The watery solution also 

 becomes turbid when spirit is added, and the alcoholic more clear by the 

 addition of water. Diluted sulphuric acid renders the aqueous solution 

 turbid, and the alcoholic more so, whilst caustic alkali changes the colour 



