54 Scientific Intelligence. 
weight was observed. In order to fix the ratio of molecules, the 
total lime was precipitated as oxalate, the total chlorine deter- 
mined by boiling with ammonia and pre ecipitation with silver 
nitrate, the available chlorine by Bunsen’s method, the calcium 
hydrate by boiling with ammonia, evaporating to aero extract- 
ing with alcohol, and weighing the residue, and the water by 
igniting with lead oxide and wees t e evolved water in a cal- 
chlorine combined with oxygen, the total chlorine less one half 
the available chlorine is the chlorine not combined with oxygen 
and the total CaO, less the free CaO, is the CaO combined with 
chlorine, all the needed values are obtained from the above data. 
Six examples of the bleaching powder were analyzed and the re- 
sults show that it contains the elements of calcium hypochlorite 
and calcium chloride in equal molecular proportions, but that the 
amount of calcium hydrate is variable, contrary to the conclusion 
of Stahlschmidt. The calcium chloride present in the bleaching 
powder was extracted by alcohol, and the total lime, the free lime, 
and the total and available chlorine determined in the residue. 
The results show that in the bleaching compound the lime is to 
the total chlorine.as 1:2, to the actual et chlorine as 1:1 
and the actual oxidizing chlorine is to the total chlorine as 1:2; 
all of which conditions are fulfilled and fulfilled only by the form- 
ula of Odling. The author therefore concludes: (1) bee the ex- 
= of calcium hydrate present in bleaching powder is not a 
constant quantity ; (2) that the anor of the bleachiig com- 
pound is Cl-Ca-OCl; and (3) that by the action of water this 
compound undergoes iecompesition as follows: ae oe 
Ca(OCl), + CaCl,.— J. Che eh xliii, 410, Oct t., 1883. G. F. 
U tubes containing ie moistened with pure sulphuric acid, 
d fragments of pure potassium hydrate, placed paciee tt 
then through Liehig’s potash bulbs. The experiment continued 
for several months, many hundred cubic meters of air se ing 
passed through the ‘apparatus. The potassium sulphites and pe 
phides were then oxidized to sulphates and the sulphuric acid 
determined as barium sulphate. As a result it appeared that each 
hectoliter of the air which passed through the apparatus contained 
0°18 cubic pense =» of sulphurous oxide or 1°8 ¢, ¢, per eubic 
meter. The experiment was repeate oe taking a time when the air 
was quiet, and the result showed 2:2 c. c. of sulphurous oxide to 
the cubic meter. On the other hand, the amount fell to 14 c. ¢. 
when the weather was we On examining the rain water of 
