300 Drs Ch. Martins and B. Gastaldi on 



exceedingly difficult to detect even a trace of it in the mother 

 liquor, from several pounds of water. Minute as this quantity 

 must be, it is nevertheless collected and assimilated by many 

 marine plants, and the following experiment enables us to 

 demonstrate its presence in their juices. If we take a thin 

 transverse sectional slice of the stem of the Fucus la7ninaria 

 digitata^ moisten it with a little starch-paste and dilute hy- 

 drochloric acid, and examine it by the aid of the microscope, 

 we shall, upon adding a drop of a solution of nitrite of potassa 

 to the same, be able most distinctly to observe the formation 

 of iodide of starch. The presence of an iodide may be shewn 

 in a still more marked manner, by suspending the stem of 

 the same plant in a dry atmosphere, when the surface, after 

 the lapse of some hours or days, will become covered with 

 numerous transparent crystals, which, on examination, will 

 be found to consist principally of chlorides, but at the same 

 time to contain so much of an iodine-compound, as to impart 

 an intense blue colour to the test mixture. 



Many marine plants, when placed in a fresh state in contact 

 with the test mixture, impart an orange colour to it, owing 

 to the liberation of bromine. — The Quarterly Journal of the 

 Chemical Society, vol. iv.. No. 14, p. 155. 



Parallel between the Superficial Deposits of the Basin of Swit- 

 zerland and those of the Valley of the Po in Piedmont By 

 Dr Charles Martins and B. Gastaldi. 



1. Ancient Moraines (part of the Terrain Cataclystique of 

 Necker). — In proceeding from the higher to the lower ground 

 in both basins, we find great accumulations in the form of 

 ridges, composed of erratic blocks, sand, angular gravel, of 

 striated pebbles, derived from the Alps, and of loam (lehm), 

 all mixed together, and without any trace of stratification, 

 indicating the long existence of glaciers at the localities. In 

 Switzerland, the towns of Berne, Zurich, Sursee, &c., are 

 built on moraines ; also the moraines of Mont Sion, between 

 Geneva and Annecy ; and, finally, the great moraine of the 



