Paper, 'Some experiments on the production of ozone' by J J [Joseph John] Thomson and R [Richard] Threlfall Thomson and Threlfall write: 'The first experiment was made in order to see whether ozone could be formed by placing oxygen in a very strong electric field, the field, however, being just not strong enough to cause sparks to pass through the gas. This experiment finally took the following form:—ABC is a box made of flat pieces of glass about 1/16th of an inch thick, fastened together with paraffin; into the box two glass tubes, G and H, are inserted, the air entering the box through G, and leaving it through H. Against one side of the box a glass bottle, D, with flat sides, is placed and filled with water containing a little sulphuric acid, this serves as one electrode; the other electrode is a blackened tin plate, E, placed against the opposite side of the box, the distance between the electrodes being an inch and a half.' Annotations in pencil and ink. Includes one diagram of experimental apparatus. Subject: Physics / Electricity Received 1 May 1886. Read 6 May 1886. A version of this paper was published in volume 40 of the Proceedings of the Royal Society as 'Some experiments on the production of ozone'. 1886