218 



Horsford, in the laboratory of Prof. Liebig, who found a much 

 less proportion than Dr. Jackson, t^o^-^j-cjo- of weight. M. Desor 

 observed that it was very difficult to account for the presence of 

 Ammonia from the presence of the Infusoria in red snow, and of 

 the minute Podurellae (Desoria glacialis), though so abundant. 



Dr. C. T. Jackson exhibited beautiful Crystals, formed in 

 a mass of cinders, which had lain undisturbed for some 

 years, at the copper-works at Point Shirley. They proved, 

 on analysis, to be a bi-sulphat of copper and zinc. 



Dr. C. T. Jackson described an interesting experiment of 

 Mr. Blake at the Gas-works. 



He placed a m:^ss of compact felspar in a crucible, hermeti- 

 cally sealed, in a furnace flue at the gas-works, where it was ex- 

 posed for 108 hours to a uniform temperature considerably below 

 the degree necessary for the fusion of the mineral. On being 

 taken out, it was found to be perfectly limpid, and transparent as 

 quartz ; showing that long-continued heat, though not to a degree 

 sufficient to melt the mineral, produces effects similar to those 

 produced by fusion. 



Dr. Gould described new Shells, received from Rev. Mr. 

 Mason, of Burmah, several of which had been furnished by 

 the lady of one of his associates, Mrs. Vinton. He repeated 

 a remark, formerly made, that the forms of land and fresh 

 water shells from our antipodes, bore a striking resemblance 

 to those of our own country ; while those from intermediate 

 regions are quite dissimilar. The shells now received give 

 additional confirmation of the fact. 



Helix anguina. Testa sinistrorsa, distorta, planorboidea, gla- 

 bra, fusco-castanea ; infra radiatim flammulata, vix concava ; 

 spira planulata, anfr. 5^ convexiusculis, ultimo ad peripheriam 

 sub-angulato ; aperlura despecta, per-obliqua, semi-elliptica, pe- 

 ristomate rufo, revoluto, callo angulato baud appresso, conjuncto; 

 lamella alba secundum anfractum penuUimum intro-volvenle. 

 Diam. 1, alt. ^ poll. Hab. Manko, near Newville, Province of 

 Tavoy. Presented by Mrs. Vinton. 



Another curious reversed, planorboid shell, like H. refuga^ 



