2 1 6 Intelligence and Miscellaneous Articles, 



into the bed dislodged the gas accumulated in the interstices where 

 it was formed j while, after dry weather had continued for some 

 time, the openings produced in this bed on drying up would draw 

 for a short time a supply of air to fill up the vacuities, and hence 

 the draft observed to pass down into the well. The whole of the 

 neighbouring district, to the extent of four miles, is called by the 

 well- diggers, foul country. Similar phaenomena were observed in 

 digging a well on the opposite hill at Applebury, and also ( in form- 

 ing some wells in the immediate vicinity of London. 



XXIV. Intelligence and Miscellaneous Articles, 



ON THE ACTION OF IODINE UPON THE VEGETABLE ALKALIS. 

 BY M. PELLETIER. 

 [Continued from vol. x. p. 503 and concluded.] 

 Iodine and Brucia. — Iodine when put into contact with brucia 

 renders it of a brownish yellow colour ; when heated with water 

 the mixture at first yields iodine, the compound softens like a resin- 

 ous body, but without perfectly melting ; on cooling it becomes 

 brittle. The solution when filtered and evaporated leaves a brown 

 substance with some traces of crystals. 



The mass is totally soluble in hot alcohol; on cooling a very light 

 brown powder separates ; the solution yields by slow evaporation a 

 further quantity of it, and towards the end of it, crystals of hvdri- 

 odate of brucia in transparent quadrilateral prisms, are obtained. 



The formation of the hydriodate of brucia appears to be derived 

 from the reaction of the iodine upon alcohol, which is well known 

 to produce hydriodic acid. A brown matter is also formed when 

 water is employed, but in this case there are mere traces of hydri- 

 odate. 



The brown matter is iodide of brucia ; with chemical agents its 

 appearances are similar to those of iodide of strychnia, except such 

 as depend upon the difference of the bases: heated with the diluted 

 mineral acids it yields salts of brucia, and with concentrated nitric 

 acid it gives the fine red colour which characterizes brucia. 



It has already been shown that the iodide of strychnia is a neutral 

 compound, but that of brucia is a bi-iodide composed of 



Two equivalents of iodine 252 or 47*72 



One equivalent of brucia 276 „ 52*28 



523 10O 



A neutral iodide of brucia was obtained by mixing and agitating 

 cold tinctures of iodine and the alkali, not adding enough of the 

 former to constitute a bi-iodide. An orange-coloured precipitate 

 is obtained, which is a neutral iodide, composed of nearly 



One equivalent of iodine 126 or 31 34* 



One equivalent of brucia 276 „ 68-66 



402 100- 



