466 Dr. Lankester, on the [F<^b. 5, 



Society if Arts— iowvnixX for Nov. and Dec. 1857, and Jan. 1858. 8vo. 

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Visits to Scotland, London, and the South- West of England in 1828, 1830, 



and 1833. 16to. 1847. 

 Treatise on Isometrical Drawing. 2nd Edition. 8vo. 1838. 

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 Vereins zur Bqforderung des Gewerhfleisses in Preussen — Sept. and Oct. 1857. 



4to. 

 Voji Kerstet\, Charles, Esq. (the Author) — Reading made Easy (for German, 



English, and French, by New Characters.) 8vo. Brussels, 1857. 

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 Zoological Society of London — Proceedings, Nos. 334-338. 8vo. 1857. 



WEEKLY EVENING MEETING, 



Friday, February 5. 



The Lord Wensleydale, Vice-President, in the Chair. 



Edwin Lankester, M.D. F.R.S. M.R.I. 

 On the Drinking Waters of the Metropolis, 



In bringing the subject of the drinking waters of the metropolis 

 before his audience, the lecturer stated that he wished to address 

 them not as a chemist or a naturalist, but as a medical officer of 

 health. He wished to make his lecture practical, and to answer the 

 question. What water shall we drink? Water might be discoursed 

 on as a solid, a liquid, or a vapour, and from every point of view it 

 had deep interest for man. It was as one of the great factors of the 

 organic kingdoms, that he must now regard it. Water was necessary 

 to the formation of the tissues of both plants and animals. Some 

 water plants consisted of from 90 to 95 per cent, of water, whilst 

 Professor Owen had estimated the solid matter of a jelly-fish weigh- 

 ing two pounds, at sixteen grains. Seventy-eight parts in the 

 hundred of blood, and seventy-two parts in the hundred of muscle 

 was water. Most kinds of solid human food contained more than 

 fifty per cent, of water. 



Water was not only necessary to the formation of animal and 

 vegetable tissues, but to the introduction into the system of saline 

 and organic matters. The water of the blood held 420 grains of 

 saline matters in solution, and the tissues also contained salts, such 

 as phosphate of lime, which were introduced by the agency of 

 water. The organised matters of the food of animals were taken 



