Page:Proceedings of the Royal Society of London Vol 4.djvu/410

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384

May 5, 1842.

The MARQUIS OF NORTHAMPTON, President, in the Chair.

Henry Frederic Link, Dr. G. S. Ohm, Jean Victor Poncelet, and Henry Rose, were severally elected Foreign Members of the So- ciety.

George Hunsley Fielding, M.D., and John Jesse, Esq., were bal- loted for and duly elected into the Society.

The reading of a paper, entitled, " Sixth Letter on Voltaic Com- binations," addressed to Michael Faraday, Esq., D.C.L., F.R.S., Fullerian Professor of Chemistry in the Royal Institution of Great Britain, &c., by John Frederic Daniell, Esq., Foreign Sec. R.S., Professor of Chemistry in King's College, London, was resumed and concluded.

The purport of this letter is to follow the consequences of the law of Ohm, and the expressions which result from it, relative to the electromotive force, and to the resistances in the course of a voltaic circuit ; to apply this theoiy to the verification of the conclusions which the author had formerly deduced from his experiments ; and to suggest additional experiments tending to remove some obscu- rities and ambiguities which existed in his former communications. In following out these principles, the author is led to offer various practical remarks on the different forms of voltaic batteries which have been proposed with a view either to the advancement of our theo- retical knowledge of the science, or to the service of the arts. The author enters more particularly into an explanation of the principles on which the cylindric arrangement of the battery he has intro- duced is founded, which appear to him to have been greatly misun- derstood. The formulae and the calculations which form the body of this paper are not of a nature to admit of being reported in the present abstract.

A paper was also read, entitled, " On Fibre additional observa- tions. By Martin Barry, M.D., F.R.S., Lond. and Ed.

On examining coagulating blood, the author finds that it contains discs of two different kinds ; the one comparatively pale ; the other, very red. It is in the latter discs that a filament is formed ; and it is these discs which enter into the formation of the clot ; the former^ or the pale discs, being merely entangled in the clot, or else remain- ing in the serum. He thinks that the filament escaped the notice of former observers, from their having directed their attention almost exclusively to the undeveloped discs which remained in the serum, and thus conceived that the blood-discs are of subordinate import- ance, and are not concerned in the evolution of fibrin.

To render the filament distinctly visible, Dr. Barry adds a chemical reagent capable of removing a portion of the red colouring matter, without altogether dissolving the filament. He employs for