TRANSACTIONS OF THE SECTIONS. 77 



substance of similar origin, but solid. It is of yellow colour, insoluble 

 in water, but soluble in alcohol, from which it separates in long rect- 

 angular prisms. Upon analysis by Mr. Scanlan and Dr. Apjolin it was 

 found to be composed of ten atoms carbon, five atoms hydrogen, and 

 two atoms oxygen. 



On the Insulation of Fluorine. By Mr. Knox. 



Mr. Knox, by operating with vessels of fluor spar, had been enabled 

 to confine this singular substance and submit it to ocular examination. 

 He separated it from fiuoride of mercury by dry chlorine, and obtained 

 it in the state of a gas of a deep orange colour. 



Dr. Dalton explained his views relating to Chemical Symbols, and 

 compared the method of representation which he advocates with the 

 method of notation sanctioned by Berzelius and other chemists. (See 

 in this volume the Address delivered by Dr. Daubeny. 



Mr. Babbage exhibited a Thermometer recently discovered in Italy, 

 and supposed to be one of those originally manufactured for the Societk 

 del CImento. It appeared to be filled with alcohol. The bulb was 

 spherical ; the stem was divided into 50 equal parts by beads attached 

 to it by fusion at equal distances. The scale of these instruments ha- 

 ving; been adopted without reference to fixed points Cas boiling water or 

 melting ice), it is a problem of some difficulty to render the results ob- 

 tained by the use of them comparable with the indications of modern 

 instruments. 



Mr. Babbage stated the progress in this research made by Libri, and 

 the methods which he had employed for the purpose. 



On a modification of the common Bellows Blowpipe. By Wm. Ettrick. 

 The author proposed to equalize the unsteady blast of the simple bel- 

 lows blowpipe, by decreasing the usual size of the blower and giving it 

 a rapid motion by means of a crank and multiplying wheels, turned by 

 the hand or foot. A valve adjustible to any degree of pressure is placed 

 on the upper bellows-board. 



On a means of detecting Gases present, in small proportions, in Atmo- 

 spheric Air. By William West, of Leeds. 

 The author proposes, by wind-sails or some similar means, to draw 

 large measured quantities of air through liquids fitted to combine with 

 the gases suspected. 



Mr. Lowe exhibited crystals of iron pyrites produced on the clay 

 which lines the iron pots, used in the manufacture of sal ammoniac. 

 (See vol, iii, p. 582.) 



