M. Baer on Animal Life in Nova Zembla. 93 



either before or after calcination ; and I was equally unsuc- 

 cessful with the enamel of human teeth, and the precipitate 

 fi'om the urine.* 



In these experiments, when I had failed in acting on the 

 glass, I always found that the addition of 0.3 grains of fluoride 

 of calcium to the experiment, produced a strong and indelible 

 mark on the surface of the glass test-plate. 1 mention 0.3 

 grains, because it will always be found sufficient to produce a 

 most unequivocal corrosion, though I obtained satisfactory re- 

 sults by the addition of a much less quantity. I have had 

 only one opportunity of examining fossil ivory ; and in that 

 instance, I could not ascertain its locality. On submitting it, 

 however, to the test used for recent ivory, bone, &c., I ob- 

 tained immediate action on the glass. In conclusion, I must 

 express my firm conviction, that fluoride of calcium, as an in- 

 gredient in fossil ivory, must be regarded as an extraneous 

 matter, introduced by the partial mineralization of the animal 

 substance ; — that no such constituent exists in recent ivory, 

 the enamel of teeth, human bone, or urine ; — in fact, that 

 fluoride of calcium should be expunged fi'om the list of the 

 constituents of animal substances. 



August 1839. 



Sketch of Animal Life in Nova Zembla (Novaia Zemlia.) 



By K. E. Von BAER.f 

 The entire absence not only of trees, but also of every shrub 

 which, without being sought for, might yet be sufiiciently 

 large to attract the eye, communicates to polar landscapes a 

 peculiar and impressive character. 



First of all, the power of measurement by the eye is lost, 

 for, owing to the want of the usual objects of known dimen- 

 sions, viz. trees and buildings, distances seem less considerable 



• I was much pleased to obsene that Mr Pepys, in an analysis of enamel, 

 published in Mr Fox's work on the Teeth, does not mention fluoride of cal- 

 cium as an ingredient of that substance. This analysis was made by Mr 

 Pepys in 1833, several years after the fluoride had been declaied a constitu- 

 ent of the enamel . 



t From " M^'ietfrnannU Arrhir/ii'r KatiirqeichU-liU.'> 1839. Part II, p. ICO. 



