Edinburgh Meeting. 28 7 



Society, and which had been printed in its Transactions. — Prof. 

 Hamilton explained a new method of conceiving imaginary quan- 

 tities, and the principles of a theory which he denominated "the 

 theory of conjugate functions." Prof. Hamilton stated, that he had 

 confirmed, by the aid of the theory, the results obtained by Mr. 

 Graves. — Mr. Sang stated the results of some theoretical and ex- 

 perimental investigations which he had made on the nature of those 

 curves traced by the extremities of vibrating wires fixed at the end, 

 and he exhibited drawings of the forms of the curves thus produced. 

 — On the Production and Propagation of Sound, by Dr. Williams. — 

 On the Visibility of the Moon in total Eclipses, by Dr. Robinson. — 

 On Collision, by Mr. Hodgkinson. 



Section of Chemistry and Mineralogy. 

 Chairman. — Dr. Hope. 



Mr. Johnston and Mr. Harcourt gave an account of the state of 

 the experiments they have respectively undertaken, on the compa- 

 rative analysis of Iron in the different stages of its manufacture, and 

 on the effects of long-continued heat. — Prof. Whewell made a com- 

 munication from the Committee appointed to examine the subject 

 of Isomorphism. — A paper was read by Dr. Charles Williams, On 

 a new law of Combustion, and the production of Flame at a low 

 temperature. — On the employment of coal-tar in connexion with 

 water as fuel, by Prof. Daubeny. — On the discoveries of Reichen- 

 bach in regard to the products of the destructive distillation of 

 organic substances, by Dr. Gregory*. —A notice of a large specimen 

 of amber from Ava, intersected by thin layers of carbonate of lime, 

 by Sir David Brewster. — Mr. Van der Toorn gave a determination 

 of the amount of water in crystallized sulphate of zinc. The total 

 amounts to 7 atoms, of which 6 are given off at 110° C, the other 

 atom remaining as a necessary constituent of the salt. From this 

 result he concluded that sulphates, which at a red heat give off sul- 

 phuric acid, contain an atom of water as an essential constituent. — 

 On the amount of carbonic acid in the atmosphere of the town of 

 Bolton, and the country around, by Mr. Watson. — On the present 

 state of our knowledge regarding contagion, by Dr. W. Henry.— 

 An analysis of the oxichloride of antimony or crystallised powder 

 of Algaroth, by Mr. Johnston. — The Rev. W. V. Harcourt described 

 the objects of the experiments now in progress under his superin- 

 tendence, for determining the effect of long-continued heat on 

 various mineral substances, and the various methods adopted by 

 him in disposing them beneath the iron furnaces of Yorkshire. — 

 Dr. Clark gave an account of Mr. Nixon's process for smelting iron 

 by the aid of the hot-blast, and exhibited numerical results of the 

 advantages derived from the new process. The saving is so great, 

 that the total amount of coal now necessary to produce one ton of 

 iron amounts only to 2 tons 14 cwt. ; whereas formerly it required 

 8 tons 1^ cwt., being a saving of 5 tons 8 cwt. for each ton of iron 

 produced. This subject was discussed at considerable length. — 



* See Lond. and Edinb. Phil. Map;, vol. i. p. 402; and vol. iv. p. 390. 



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