4*76 Canadian Record of Science. 



ination some very interesting specimens of these minerals, 

 collected by him at the '• 100 ton pit," McLaren's Phosphate 

 Mine, lot 4, concession 8, North Burgess, Lanark Co., Ont. 



They present all the ordinary physical characters of 

 these species. 



The anhydrite is in cleavable masses of a light purple or 

 lilac color, and shews alteration to a snowy white gypsum, 

 being in places, traversed by a network of little cracks filled 

 by that mineral, a process of alteration apparently analo- 

 gous to that of tbe serpentinization of olivine. Sometimes 

 the alteration has taken place only in the direction of the 

 cleavage planes, giving rise to a most beautiful banded 

 structure, anhydrite and gypsum arranged in alternate 

 layers. 



Some good sized masses of fine-grained white gypsum 

 occur with the anhydrite, probably derived from its altera- 

 tion. 



Both the anhydrite and gypsum occur in ciystalline 

 limestone, associated with apatite, and their presence in 

 the Laurantian limestones is of special interest, opening 

 up, as it does, many interesting questions regarding the 

 origin of these limestones. 



Hitherto the sulphates of lime seem to have been over- 

 looked in enumerating the minerals of the Laurentian. 



It is purposed to make a careful study of the mode of 

 occurrence of these sulphates in the Laurentian limestones, 

 and to publish any interesting facts which may be ascer- 

 tained regarding it. 



Ottawa, Xov. 24, 1891. 



David Milne Home. 



L.L.D. F.E.S.E. F.G.S. &c. 



David Milne, afterwards David Milne Home, was born 

 January 22nd, 1805, and died, full of years and honours, on 

 September 19th, 1890. His father was a captain in the 

 Boyal Navy, a distinguished officer, afterwards Admiral 

 Sir David Milne, and David was the eldest son, and from 



