236 Scientific Intelligence. 
sulphate, or nitrate of ammonium the dissociation of these salts 
may be shown.— Bull. Soe. Ch., 11, xxxvi, 545, December, 1881. 
regulator, with the porcelain crucible in close proximity to it, 
covered by its lid. A thermometer bulb was placed near it, the 
iron pot was covered and heated with a Fletcher’s burner. The 
air bath was first heated for a half-hour to the temperature of the 
experiment. The crucible with its mixture was inserted, and the 
heat continued for four hours. At the end of the time the crucible 
being gradually increased from a decigram to ten grams, the tem- 
perature being kept at about 195°. If the action of ferric oxide 
upon potassium chlorate be similar to that of an ordinary oxide 
upon an ordinary salt the numerical results should admit of rep- 
. ee x a y = 
resentation under some form of the general equation EK = ~~ m 
which E is the chemical effect on oxygen expelled, # and y are 
e mas 
ical effect, the number of chemical units of oxygen expelled pet 
unit of oxide. The results suggest that the values of a are in 
versely proportional to the values of a. Calculation upon this 
hypothesis gave results closely agreeing with experiment. _ When 
# is very small, a = 33028, and (Fe,O,), expels O,, or a unit of the 
oxide acts on rather more than a unit the chlorate. When 7 1s 
very large, a=0°27240, and the five grams of chlorate reaches the 
limit of 071775 gram oxygen expelled. Moreover as the mass. of 
oxide increases its efficiency decreases. Inasmuch as in the action 
of ferric oxide on potassium carbonate, the factor of chemical 
effeci, in the first stage, is inversely as the mass of oxide, the 
authors regard the entire course of the action of ferric oxide upon 
potassium chlorate as strictly analogous to the first stage of the 
action of the same oxide on potassium carbonate. This case of 
chemical change then presents nothing peculiar or abnormal and 
the name catalysis ceases to be applicable to the reaction now con- 
sidered.—J. Chem. Soc., xli, 18, Jan. 1882. ciel ek 
4. On the Freezing point of Sulphuric acid of different Degrees 
of Concentration.—Lunexr has determined the point at whic 
sulphuric acid of various strengths solidifies when exposed to cold. 
A freezing mixture of three parts ice and one of salt was used, 1m 
