Fror. Graham on Pnosphot'tc Acid in Water. 369 



benzoic acid, so that the result obtained is exactly what might 

 have been expected from the action of nitric acid on a carbu- 

 retted hydrogen of the benzoic acid series containing a little 

 .oil of bitter almonds. ^ . 



, ,'In conclusion, I may mention that the production p^|tuis 

 oil, from its striking and peculiar properties, furnishes an ex- 

 cellent test for detecting the presence of cinnamic acid. 



A quantity of the chlorinated oil was also treated for some 

 days, both exposed to the light of the sun and in diffused light, 

 with dry chlorine, in the hope that perhaps a crystalline com- 

 pound might be produced. In this however I was unsuccess- 

 ful; much muriatic acid was given off and the liquid became 

 tolerably viscid, but no crystals were formed. 



LVL Note on the Existence of Phosphoric Acid in the Deep- 

 1 Well Water of the London Basin. By Thomas Graham, 

 Esq., F.R.S.^ 



THIS water is obtained on piercing the London clay, which 

 forms an impervious bed, generally exceeding 200 feet 

 in thickness, and flows from fissures in the subjacent chalk. 

 It is always highly soft and alkaline, and remarkable for the 

 predominance of soda salts over earthy salts among its solid 

 constituents. I have never found it to contain a sensible quan- 

 tity of potash, although salts of the vegetable alkali appear 

 among the constituents of the water of the deep Artesian well 

 of Grenelle. 



When evaporated considerably, a small deposit takes place 

 in the London deep-well water, which consists chiefly of car- 

 bonate and phosphate of lime. The remaining liquid gives 

 with nitrate of silver a precipitate of chloride and carbonate 

 of silver, which is white without any shade of yellow; but if 

 a portion of the water, amounting to an ounce or two, be eva- 

 porated to dryness in a platinum capsule, without removing 

 the precipitate, and the heat afterwards continued so as to 

 raise the temperature of the resulting dry saline matter to low 

 redness, then, on redissoKing -by distilled water, and adding 

 nitrate of silver, a precipitate is obtained, in which the yellow 

 colour of the phosphate of silver is very perceptible. The 

 earthy phosphate is decomposed by ignition with the alkaline 

 belonging to the water, and the soluble phosphate of soda is 

 produced. 



The following are the results of the analysis of the water 

 from the deep well in the Brewery of Messrs. Combe and 



Communicated by the Chemical Society; having been read May 5, 

 1845. 

 Phil. Mag. S. 3. Vol. 27. No. 1 8 1 . Nov. 1 845. 2 B 



