188 ANNUAL OF SCIENTIFIC DISCOVERY. 



not colored by the chloride of tin. M. Maumene, in Comptes Rendus, 

 March 18. 



PRESENCE OF FLUORINE IN BLOOD, MILK, AND SEA-WATER. 



IN 1816, Dr. Wilson, in announcing to the British Association the 

 discovery of the existence of fluor-spar dissolved in many spring-wa- 

 ters, and also the fact of the solubility of this substance in water to a 

 considerable extent, expressed an opinion that, in consequence of its 

 dissemination to such an extent, fluorine would be found in blood and 

 in milk. At the last meeting of the Association, Dr. Wilson stated 

 that he had succeeded in verifying this opinion. From the residue 

 obtained in the evaporation of three gallons of bullock's blood, sufficient 

 fluorine was obtained to etch glass with great distinctness. Like evi- 

 dence was also obtained from a similar treatment of the blood of a 

 horse. It is therefore highly probable that fluorine is a constituent in 

 the blood of nearly all animals. As regards its presence in milk, the 

 ashes of 12 Ibs. of new skim-milk cheese afforded a vapor which occa- 

 sioned deep etchings in glass. The same was true of the residue ob- 

 tained from evaporating 9 imperial pints of rich new milk ; 4 pints 

 treated in a like manner gave a faint trace of the presence of fluorine. 

 In all these instances, it probably exists as fluoride of calcium. Dr. 

 Wilson remarked that fluorine also existed in urine and in the bones of 

 nearly all classes of animals. The extent of the solubility of fluor-spar 

 in water, as determined by Dr. Wilson after repeated trials, is 0.2G gr. in 

 7,000 grains, or 16 fluid ounces. This amount, though comparatively 

 small, is large for a salt reputed to be insoluble. Jameson's Journal, Oct. 



Fluorine in Sea-Water. At the meeting of the British Association 

 in 1849, Dr. George Wilson announced the discovery of the presence 

 of fluorine in the waters of the German Ocean and in the Friths of 

 Forth and Clyde.* Since that announcement, incrustations deposited 

 in the boilers of steamers navigating the English Channel, the Atlantic, 

 and the Mediterranean have been procured and examined. All yielded 

 under proper treatment hydrofluoric acid, the two latter abundantly. 

 Prof. Forchhammer of Copenhagen, from experiments made with the 

 waters of the Baltic, estimates the quantity of fluoride of calcium in 

 100 pounds of the water of the ocean, which contain from 3.5 to 4 per 

 cent, of salts, to be about 1 grain. Prof. Forchhammer has likewise 

 proved the existence of phosphoric acid in sea- water. From these va- 

 rious experiments, says Dr. Wilson, we may infer, that, as the sea 

 within narrow limits is very uniform in chemical composition, fluorine 

 will be found universally present in the ocean. Indirect proof had be- 

 fore been obtained from its presence in corals and shells, as well as in 

 marine fishes and Mammalia. Jameson's Journal, April. 



ALIMENTATION OF COFFEE. 

 A PAPER with the above title has been recently read before the 



* See Annual of Scientific Discovert/, 1850. p. 201. 



