1866. | Chemical Science. 531 
paraffin oil, and of crude oil and ‘petroleum for spirit, photogen, 
lubricating oil, and paraffin, Dr. Stevenson:Macadam gave an ac- 
count of some experiments in which he had been engaged on the 
poisonous nature of crude paraffin oil and the products of its 
rectification. His attention had been drawn to the subject on 
account of the great mortality which had taken place among the 
fish in some Scottish streams, and the experiments fully proved that 
the destruction had been caused by the discharges from paraffin oil 
works, 
Dr. Daubeny opened the meeting the next morning with a paper 
on Ozone. His researches tended to show that the atmospheric 
ozone was almost entirely due to plants, the green parts of which 
generate ozone, whilst they emit oxygen. ‘The flowers generate no 
ozone, 
Mr. Spence then described a new and probably important 
process for manufacturing white lead. It consists briefly in 
dissolving oxide of lead (from poor lead ores) in caustic alkali, and 
then precipitating by carbonic acid. The process was illustrated 
before the meeting. 
Mr. Crookes then read some notes on Disinfection, principally 
in reference to the present outbreak of cholera in London. He 
gave several examples of the ignorance and waste characterizing 
the employment of disinfectants in different parts of London, and 
pointed out the absurdity of using at the same time, in the various 
parishes of London, disinfectants that were incompatible with one 
another. In one parish strong oxidizing disinfectants were largely 
used, in the adjoinmg one powerful deoxidizing disinfectants were 
employed; so that when the streams of sewage met from the 
different districts, the several agents exerted reciprocally an antago- 
nistic action, thus expending their energies in mutual destruction, 
instead of uniting them in serviceable work. It was shown that 
oxidizing disinfectants were quite inadequate to cope with an evil 
of any great magnitude, but that antiseptics could be fully relied 
upon. 
The principal paper of general interest the next day was one 
by Mr. Larkin, on the Magnesium Lamp. The distinguishing 
peculiarity of these lamps is that they burn magnesium in the form 
of powder instead of ribbon or wire. The metallic powder, mixed 
with sand as a diluent, is contained in a large reservoir, from 
which it flows through a tube at the bottom. Upon reaching the 
orifice, the metallic powder ignites, and burns with a brilliant flame. 
A small jet of gas issuing from the same orifice affords a permanent 
means of ignition, and the flow is regulated or shut off by a valve. 
At the first soirée in the Mechanics’ Hall, where these lamps were 
exhibited, some complaint arose on the part of the ladies present, 
