J. P. Cooke on Stibiotrizineyle and Stibiobizincyle. 231 
A mere glauce at the table will discover two facts: 
Ist. That up to 50 p.c. no great increase in the amount of 
hydrogen evolved is obtained by increasing the amount of anti- 
mony in the alloy. 
2nd. That at the alloy containing 58 p. c. of commercial anti- 
mony, or about 57 p. c. of pure antimony, there is an immense 
maximum which is confined between at most two per cent. on 
either side. 
fore passing to the result to which the last of these facts di- 
rectly points, I will briefly state the few additional facts which I 
ave observed in regard to the decomposition of water by the 
autimony alloys. 
It isa well known fact that the rapidity of the evolution of 
hydrogen from dilute sulphuric acid and zine can be very greatly 
Increased by adding to the materials a few drops of a solution of 
chlorid of platinum. The platinum being immediately deposited 
on the zine, forms with it a galvanic pair, and thus increases the 
affinity of the zinc for oxygen. The same increased action can 
produced by the same means in the decomposition of pure 
Water by the antimony alloys. Column 2 of the table gives 
the results which were obtained by boiling with pure water ina 
small flask 200 grammes of the granulated alloys, previously 
tteated with the same amount in each case of a solution of chlo- 
steat uniformity can be expected on comparing the results. The 
main facts however noticed in columns 1 and 3 of the table 
are quite as prominent in column 2, and also the additional fact 
that the presence of platinum very greatly increases the rapidity 
of the evolution of hydrogen from the alloys 
One set of results given in the table requires particular notice ; 
those obtained from pure zinc to be found on the first line oppo- 
f ; 
count the experiments with pure zine were e with peculiar 
ere 
Which 
aliinity of the zine is strengthened by the galvanic action of the 
Platinuny, 
