465 



substances. For the present I limit myself to noting the date, and asking 

 the Academy to give rae formal acknowledgment of this communication." 



From the statement of Nickles, which I have quoted in full, it 

 will be seen that its author was led by his verification of the con- 

 clusion, first announced at Rome by Morichini and Gay-Lussac in 

 1802, that fluorine occurs in the bones of animals, to infer that it 

 must be conveyed to these organs by the blood, and to seek for it in 

 that fluid. 



The majority of analysts, however, have long ago justified the 

 early Roman observations. In particular the question of the pre- 

 sence of fluorine in bones was keenly contested in London in 1 843, 

 and analyses confirmatory of its occurrence in them were published 

 by Professor Daubeny and Mr Middleton; to which in 1846 I 

 added, in a communication made to this Society, the accordant re- 

 sults obtained by Professor Gregory and myself, and drew attention 

 to the suggestion of Professor Graham of London, and of Dana, the 

 American geologist, that animals possibly derived the fluorine found 

 in their tissues from fluoride of calcium held in solution by water 

 containing carbonic acid. In the same paper I adverted to the con- 

 clusion of Mr Middleton, founded on his detection of fluorine in a 

 multitude of aqueous deposits, that " beyond a doubt it is present in 



water, though perhaps in very minute quantity The simple 



tact that the blood conveys it to the bones would, I apprehend, suflfi- 

 ciently confute any scepticism on the subject." 



At this point I took up the inquiry in January 1846, and on 

 April 6 of that year communicated a paper to this Society, in the 

 " Transactions" of which it was published. It will be sufficient here 

 to give an epitome of its contents. The paper was entitled "On 

 tlie Solubility of Fluoride of Calcium in Water, and its relation to 

 the occurrence of Fluorine in Minerals, and in Recent and Fossil 

 Plants and Animals.'* It is divided into seven sections. The first, 

 entitled " Introductory Remarks," details the researches of my pre- 

 decessors, including those to which I have just referred. The second, 

 entitled " Of the Solubility of Fluoride of Calcium in Water," points 

 out, that, contrary to previous belief, this salt is dissolved by pure 

 water, yielding a solution answering to all the tests of lime and of 

 hydrofluoric acid. The third, entitled " Of the presence of Fluorine 

 in Well, River, and Sea Watrr," confirms and extends the observa- 



