Notes. 
769 
1879.] 
tuted by Dr. J. Konig. These researches relate, in the first 
place, to the waters from certain mines of zinc-blende in West- 
phalia, which pass into certain streams used for irrigation, and 
seriously injure the productiveness of the soil. The presence of 
zinc oxide in the earth is indicated by the presence of Viola 
calaminaria , which contains in its ash as much as 21 per cent 
zinc oxide. The author has likewise examined the waste waters 
from a dye works, a wire works, and from pyrites washing. The 
two latter he considers as directly poisonous to plants on account 
of their percentage of ferrous sulphate. The dye water may, by 
reason of the organic matters which it holds in solution or sus- 
pension, gradually overload the soil with humus, and render it 
boggy. 
M. de la Bastie is said to have made great improvements both 
in the method of tempering glass and in the quality of the 
product. Among the articles shown to the French Societe 
d’Encouragement are mortars with their pestles for chemical use. 
At the Liverpool Meeting of the Iron and Steel Institute Mr. C. 
Wood described the process of Mr. Frederick Siemens, of Dres- 
den, for the employment of toughened glass for sleepers and 
chairs for railways and tramways. Mr. Siemens tempers and 
moulds the glass into various forms to suit the different require- 
ments. The cooling of the glass is so regulated that the radia- 
tion from each point of the surface corresponds to the thickness 
of the glass, thus enabling the casting to be equally affected 
throughout when undergoing the tempering or hardening process. 
The regulation of the radiation or absorption of the heat in the 
thicker parts of the casting is done by having hollow iron 
moulds, and by circulating cold water or cool air at those points 
where the glass is thickest, so that the casting cools equally all 
over. The toughened glass is found to be almost as strong as 
iron, and it possesses greater durability. Mr. Bucknall, C.E., 
proposes to make the sleepers out of blast-furnace slag, under 
Mr. Buckley Bullan’s process combined with the toughening 
process of Mr. Siemens. 
At the Meeting of the Academy of Sciences on October 13th, 
M. Berthelot explained the plan of his new work “ Essay on 
Chemical Mechanics founded upon Thermo-Chemistry.” The 
first volume of this work is devoted to calorimetry. The second 
volume comprises the general study of chemical composition and 
decomposition. The remainder of the work is devoted to che- 
mical statics. 
A new manure is proposed by M. de Molon. Finely-ground 
phosphate of lime is mixed with sea-weeds, especially varec, the 
mass being allowed to ferment for six to eight weeks. 
A statement is quoted in “ Les Mondes ” of October 2nd, from 
the New York “ Popular Science Monthly,” that a Boston che- 
mist found in a sample of cream of tartar 75 per cent of terra 
