ON THE PREPARATION OF SODA AND CHLORINE. 39 



thin plate which partially divides the triangular chamber of the 

 yentral valve. In the only specimen collected, the beak and area 

 are distorted being turned to the left. This is not the result of 

 pressure, but owing to an irregularity in the growth of the shell. 



Dorsal valve moderately convex with a large rounded mesial 

 fold, and. two others obscurely developed, one on each side. 



Surface not well preserved in the specimen, but apparently 

 smooth with some lamellose lines of growth. In one specimen 

 the shell appears to have an inner coarsely punctate layer. 



The spires at their bases, or where the two cones abut against 

 each other, base to base, extend from the hinge line to the front 

 margin, but they rapidly diminish in diameter outwards and be- 

 come sub-cylindrical near the cardinal angles. 



The specimen when perfect must have been at least 18 lines 

 wide on the hinge line ; length of dorsal valve 8 lines ; length of 

 ventral valve from the beak to the front margin 1 2 lines ; height 

 of area about 6 lines, width of foramen on the hinge line 3 lines. 



Along the edge of the open part of the foramen, there are 

 some indications that the del tidium, when perfect, extended nearly 

 to the beak. 



Locality and Formation. — Township of Walpole, Canada 

 West ; Corniferous limestone, Collected by J. De Cew. 



Art. IV. — On a new method of preparing Chlorine, Car- 

 bonate of Soda, Sulphuric Acid and Hydrochloric Acid ; 

 by Thomas Macfarlane! 



In a former paper * I had occasion to describe the nature of 

 the reactions which take place on calcining iron pyrites with a 

 small proportion of common salt. These reactions I supposed to be 

 as follows : — First, the greater part of the sulphur of the pyrites 

 is oxidized by the air, and disengaged as sulphurous acid, the 

 iron also combining with oxygen and forming peroxide of iron. 

 At a later stage of the operation, part of the sulphurous acid 

 formed comes in contact with the peroxide of iron, and is through 

 its agency further oxidized into sulphuric acid, which combines 

 with the iron oxide, forming finally a comparatively small quan- 

 tity of sulphate of peroxide of iron. This salt reacts 

 on the chloride of sodium, producing sulphate of soda and 



* Canadian Naturalist for 1862, p. 194. 



