Recent and Fossil Bones, 261 



with which the authorities of the University College acceded 

 to my request for materials, as well for this as for my more 

 laborious investigations, left me no difficulty, and deserves 

 my best acknowledgements. 



I easily obtained conclusive evidence of the presence of 

 fluorine in the following portions of the human skeleton, the 

 bones operated upon being from the dissecting-room : — The 

 occijmt, the vertebra:^ the humenis, the Jemur, the teet/t, the 

 femur of a foetus of 6^ months. 



I examined also the arm, including the scapula, of a foetus 

 of 3| months, but could obtain no evidence of the presence of 

 fluorine in it, a result which, considering the small quantity of 

 osseous matter involved, was, perhaps, to have been looked for. 



I determined also the presence of fluorine in the entosternal 

 bones of the sternum of a recent tortoise. 



Any one who may continue to entertain doubts on this 

 subject, and whose object is the recognition and discovery of 

 truth, may readily convince himself by using the means era- 

 ployed by me. I broke a portion of the bones to be examined 

 into small fragments, and subjected them to the action of con- 

 centrated sulphuric acid in a platinum crucible covered, as is 

 usual in such operations, by a plate of glass endued with an 

 etched coating of wax. 1 applied the flame of a spirit-lamp 

 from time to time, so moderating the heat as to sustain action 

 of the acid upon the materials without projection upward of 

 the substances against the glass. I prevent the melting of the 

 wax by keeping a muslin rag moist with alcohol upon its 

 upper surface. The time occupied by each experiment was 

 between five and ten minutes. 



Through these and other investigations above alluded to, I 

 have ascertained the presence of fluorine in the organic re- 

 mains of Carnivora, Herbivora, Reptilia, Pisces, as also in 

 the recent bones of men and reptiles. The increase of fluorine 

 in fossil bones is apparently greater in proportion to the re- 

 moteness of the period at which they lived, where the cha- 

 racter of entombment is similar. These facts, taken con- 

 jointly, seemed to me to need for their explanation a more 

 general source of fluorine than has been heretofore I believe 

 supposed. It occurred to me that ordinary water might be 

 the vehicle, and if so, the presence of fluorine in recent bones 

 would not only be accounted for, but also its accumulation in 

 fossil bones, being filtered from the moisture circulating in the 

 earth's crust. In order to ascertain whether facts would be 

 found to sustain this view, I examined the following sub- 

 stances : — 



