Early next morning, Dr.Paris received the following note:-- 'Dear Sir,--The oil you noticed yesterday turns out to be liquid chlorine.
'Yours faithfully, 'M.

Faraday.'[2] The gas had been liquefied by its own pressure.

Faraday then tried compression with a syringe, and succeeded thus in liquefying the gas.
To the published account of this experiment Davy added the following note:--'In desiring Mr.Faraday to expose the hydrate of chlorine in a closed glass tube, it occurred to me that one of three things would happen: that decomposition of water would occur;...

or that the chlorine would separate in a fluid state.' Davy, moreover, immediately applied the method of self-compressing atmosphere to the liquefaction of muriatic gas.

Faraday continued the experiments, and succeeded in reducing a number of gases till then deemed permanent to the liquid condition.