336 Analysis of Scientific Books and Memoirs. 



Steel articles, &c. may be very well preserved if buried in powdered 

 quick- lime. 



From a number of experiments I bave made by suspending, by means 

 of a silk, &c. tbread, finely polished and magnetized steel bars in lime water, 

 so as to float freely in this medium from the point of suspension, I have 

 concluded that it points out an admirable method by which the magnetic 

 virtue may be preserved for an indefinite period. A ring of iron, inclining 

 to the " angle of no attraction" pointed out in Mr Barlow's Researches, 

 might surround the phial or little glass globe, and the cardinal points be 

 engraved by a diamond on a circular line externally. Under these circum- 

 stances, poised in an uniform medium of unvarying density, no atmo- 

 spheric mutations would disturb it, and the finely polished steel needle 

 would be preserved even free from oxidation, the fatal antagonist to mag- 

 netism. 



6. Improvement of Candles. By John Murray, F. L. S. and Lecturer 



on Chemistry. Communicated by the Author. 

 I steep the cotton wick in lime water, in which I have dissolved a con- 

 siderable quantity of nitrate of potassa, {chlorate of potassa answers still 

 better, but is too expensive for common practice,) by this means I secure a 

 purer flame, and superior light ; — a more perfect combustion is insured, — 

 snuffing is rendered nearly as superfluous as in wax candles, and the candles 

 thus treated do not " run." The wicks must be thoroughly dry before 

 the tallow is put to them. 



Art. XXVI.— ANALYSIS OF SCIENTIFIC BOOKS AND ME- 

 MOIRS. 



I. — A Brief Account of Microscopical Observations on the Particles con- 

 tained in the Pollen of Plants ; and on the general Existence of Active 

 Molecules in Organic and Inorganic Bodies. By Robert Brown, 

 F. R. S., Hon. M. R. S. E. & R. I. Acad., V. P. L. S., &c. 

 The very able pamphlet, of which the above is the title, though printed 

 by its distinguished author, is not published, and has been circulated only 

 among his scientific friends. We proposed at first to lay before our read- 

 ers only an analysis of it ; but this we find to be impracticable, both from 

 the nature of the subject, and from the mutual dependence of its parts. 

 We have therefore printed the whole of it, and we doubt not that the scien- 

 tific reader will look forward with the same impatience that we do to the 

 more minute details which Mr Brown has promised in a future work. 



" The following observations have all been made with a simple micro- 

 scope, and indeed with one and the same lens ; the focal length of which 

 is about^d of an inch.* 



• This double convex lens, which has been several years in my possession, I ob- 

 tained from Mr Bancks, optician, in the Strand. After I had made considerable 

 progress in the inquiry, I explained the nature of my subject to Mr Dollond, who ob- 



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