FLUORIDE OF CALCIUM. 425 



Both Middleton* and von Bibraf have very carefully analysed 

 the bones of various classes of animals, and have recognised the 

 presence of fluoride of calcium not only in the bones of the mam- 

 malia, but also in those of birds, fishes, and reptiles, and even in 

 the shells of the mollusca. Middleton 's assertion that the bones of 

 a 6^ months' fretus contain as much fluoride of calcium as those of 

 an adult, must be regarded as doubtful, till confirmed by further 

 experiments. 



Fluoride of calcium was first discovered in fossil ivory by 

 MorichiniJ ; it has since been found in all fossil bones by Proust, 

 Fourcroy and Vauquelin||, Chevreul^f, Brandes**, Bergemannft, 

 Marchand, von Bibra, Middleton, and others. Lassaignett found 

 as much as 15 in the teeth of an Anoplotherium, and I found 

 16-g- in the outer portion of one of the ribs of the Hydrarchos. 



[The presence of fluorine in blood and milk has been clearly 

 demonstrated by Dr. George Wilson ||||. G. E. D.] 



In regard to the origin of the fluoride of calcium we cannot 

 doubt that the small quantities found in the animal body may be 

 easily conveyed into the system with the food; we need only 

 remember that many mineral waters contain traces of fluorides, 

 and that plants take up a little fluoride of calcium from micaceous 

 soils. 



Fluoride of calcium was detected by Berzelius in the Carlsbad 

 water, and has been found in other mineral waters; moreover, 

 artificially prepared fluoride of calcium is by no means perfectly 

 insoluble in distilled water. [According to Wilson 16 fluid ounces, 

 or 7000 grains of water at 60 F, dissolve 0*26 of a grain of fluor 

 spar. G. E. D.] 



Whether the large quantities of fluoride of calcium which have 

 been found in fossil bones are solely due to infiltration from 

 without, must remain for the present undecided. 



* Philos. Mag. T. 25, p. 14. 



f Op. cit. 



J A. Gehl. J. Bd. 3, S. 625 ; N. Gehl. J. Bd. 2, S. 177- 



N. Gehl. J. Bd. 2. S. 187. 



|| Ann. d.Chim. T. 57, p. 37. 



IT Ibid. p. 45. 



** Schweigg. Journ. Bd. 32, S. 505. 



ft Ibid. Bd. 52, S. 145. 



tt Journ. de Pharm. T. 7, p. 1. 



Cams, iiber den Hydrarchos. Dresd. 1846. 



HI) Edin. New Phil. Journ. Oct. 1850. 



