Physics and Chemistry. 111 
the first. surface is concave, so as to admit the addition of a double con- 
vex lens of crown glass, appears to be preferable for the spectroscope, in 
consequence of the saving of light.” 
New York, Nov. 28, 1862. 
II. CHEMISTRY. 
2. On the preparation of Ozone—Scninpetn has given a method of 
obtaining ozone —QO) in comparativgky large quantities and with great 
gas evolved collected over water. The gas obtained in this manner 
Possesses all the properties of ozone as obtained by the slow oxydation 
o phosphorus or by electrolysis. Taken into the lungs it produces con- 
traction of the chest and catarrh. It destroys organic coloring matters 
With the greatest energy ; burns pyrogallic acid completely to carbonic 
_ Mid and water; does not combine with water to form H 2, but reduces 
Peroxyd of hydrogen to water, losing its smell and power of oxydation; 
. oxydizes lead, silver and arsenic in the cold; liberates iodine from me- 
tallic iodids; oxydizes the protoxyds of lead and manganese to peroxyds; 
atin sulphids into sulphates, and changes ferrocyanid to ferrideyanid 
‘a Potassium, The gas thus possesses all the properties of ozone: it is 
fi Wever only a mixture of a small quantity of ozone with a large quan- 
ty of neutral oxygen. The author remarks that it is only the gr 
yyution of the hypermanganate which yields ozone in the above process. 
ieiivat sulphuric acid is so dilute as to give a red solution no ozone is 
Bérrerr claims priority in the discovery of the above method of pre- 
Paring ozone, recommends a mixture of two parts of dry yperman- 
Sahiate of potash with three of sulphuric acid, and finds that the addition 
0 i i t 
: flowers of sulphur are instantly converted into sulphuric acid, the 
B re cag attended by an explosive noise.—Journal fur cfg toms 
‘q ’ P 40 and 377, as 
wey OM the allotropic form of Oxygen.—Scuonsetn has further endeay- 
ase ‘o strengthen his position in regard to the existence of a positive and 
negative oxygen, +O and —O, by the following facts. Strips of 
Pet soaked in a solution of sulphate of manganese are rapidly rendered 
Mnd 24.70 iB consequence of the formation of peroxyd of mangane 
or --O produces no such change, but on the con- 
is 
~ ved by hanging’ strips of darkened paper over a vessel in which 
7 Serb by the. ation of sulphuric acid a ary of barium, 
