Royal Society. 461 



-which includes the 6va of sharks : these he respectively 

 analysed^ and found them to possess similar properties, but 

 all very different from gelatin, however analogous in their 

 external appearance, and which he concluded to be a pe- 

 culiar animal innttcr not yet described. This jelly-like 

 matter is insoluble by water, but it absorbs water in great 

 quantities, and iaecomes proportionally enlarged in conse- 

 quence : acids and alkalies, however, dissolve it; but in. 

 none of its characters does it evince any identity with ge- 

 latin or albumen. 



A mathematical paper on multi-nomials, by Mr. Knight, 

 was communicajed to the secretary (Mr. Davy), and laid 

 before the society ; but it was not of a nature to be read. 



Mr. Hubbard communicated a letter from Sir John , 



containing a plan fur purifying the air of coal-mines. 

 The author, having observed that workmen descend into 

 wells with the greatest safety after throwing a quantity of 

 water into them, proposes the like expedient to purify coal- 

 mines, by projecting water, in quantities sufficient to absorb 

 the choke-damp (carbonic acid gas), against the cieling of 

 mines, by means of an instrument like a fire-engine, made 

 with an end like that of a watering-pot, to throw the water 

 like a shower-bath, and thus present the greatest possible 

 surface to the noxious air. This machine, the writer con-' 

 eludes, might be both supplied with water and v/orked by 

 the steam-engines in all coal-mines. Several other minute 

 operations and less important advantages were stated as 

 likely to result from the adoption of this plan j on con- 

 cluding which^ the society adjourned till 



June 21. — when a part of a, paper by M. Delille, 

 translated from the French, was read, describing the 

 lohan upas, or poison-tree, of Java. The author is a French 

 physician, a member of the NationalTnstilute of Egypt, 

 and transmitted this paper from the East Indies to the 

 Royal Society, by means of an English lady. The botani- 

 cal account of this poisonous plant he received from one 

 of the French naturalists who accompanied Capt. Baudin, 

 ^nd who resided sometime in Java; where he visited the 

 interior of ihe country/ and with much difficulty succeeded 

 in prevailing on the natives to show him the different poi- 

 son plants, which they carefully conceal in order to use 

 them diu^ing war. Hence the reason of so many fables as 

 have been repeated respecting the extraordinary destructive- 

 ness and influence of the zipas, which in the language of 

 the Javanese signifies vegetable poison, and is applied only' 

 to the juice of the bohan tree, and atiother twisled-stemnleci 



plant. 



