140 JOURNAL OF THE PLYMOUTH INSTITUTION. 
crimson riband of light produced by the discharge from a powerful 
induction coil through an exhausted receiver containing a slight 
residue of atmospheric air. The other prismatic tints might be 
due to the decomposition of the light by the particles of moisture 
in the denser strata of the atmosphere. 
Time would only allow a brief allusion to the connection between 
magnetism and the Aurora Borealis, and its probable effect on the 
chemical condition of the atmosphere in the development of ozone. 
The lecturer concluded by expressing his opinion that the Aurora 
Borealis depended much upon the meteorological conditions prevail- 
ing in the tropical regions during the previous summer season. 
SULPHUR 
ABSTRACT OP MR. R. OXLANd's PAPER 
(Read February 16tli, 1871.) 
The lecturer stated that sulphur is the basis of the chemical 
manufactures of the United Kingdom, its consumption amounting 
to about 1000 tons per diem. Although it is more frequently 
found in the native state than any other elementary body, yet it 
is principally characterised by its agency in mineralizing metals 
and other bodies, and by its forming remarkable constituents of 
organic bodies, both vegetable and animal. 
Some of its principal minerals were shewn and described. Its 
Geological distribution was glanced at, and its physical and 
chemical properties illustrated. The combinations of sulphur with 
hydrogen, chlorine, carbon and the metals, were described and 
their uses illustrated. The methods of extracting sulphur from 
its ores, of refining it, and producing it in the varied forms of 
block, stick, sublimed, and milk were noticed, and the uses of it 
for the manufacture of gunpowder, for dusting vines to protect 
them against the vine disease, for the manufacture of vulcanized 
India Rubber, were described. Attention was specially directed to 
the combinations of sulphur with oxygen. 
The properties of sulphurous acid as a bleaching agent, as an 
antichlore, as a disinfectant were illustrated, and its applicability 
for preserving meat and for the destruction of sewer gases pointed 
out. 
The constitution of sulphuric acid was considered, the method 
