C 159 H 
VIII. 0 /z the primitive Crystals of Carbonate of Lime, Bitter- 
Spar, and Iron-Spar. By William Hyde Wollaston, M. D. 
Sec. R. S. 
Read February 13, 1812. 
Wh en I formerly described to the Society a goniometer* 
upon a new construction for measuring the angles of crystals, 
I expressed an expectation that we should thereby be enabled 
to correct former observations made by means of less accu- 
rate instruments. I took occasion to mention one instance of 
inaccurate measurement in the primitive angle of the common 
carbonate of lime ; and I have had the satisfaction to find the 
necessity of a correction, in that instance, confirmed by Mons. 
Malus, and admitted by the Abbe Hauy, in a work •f* pub- 
lished nearly at the same time. 
It is by no means my design to detract in any degree from 
the merit of that justly celebrated crystallographer, to the sur- 
prising accuracy of whose measurements I could, in various 
instances, bear testimony. I hope, on the contrary, that in 
bringing forward two more observations similar to the pre- 
ceding, and intimately connected with it, I shall offer what 
will not only appear interesting to crystallographers in gene- 
ral, but will be peculiarly gratifying to the Abb6 Hauy. 
In his Traite de Mineralogie, and again more recently in 
his Tableau Comparatif, the same primitive form is assigned 
* Phil. Trans. 1809. 
f Tableau Comparatif des resultats de la Crystallographie et de 1 ’ Analyse Chimique. 
