On the 10th the exposure to the light had been continued two days without result. In the middle of August he experimented on the action of potassium on silicated fluoric gas. From September 2 to December 20 there are no entries in the Laboratory Book. That day--the first after his return from Ireland--there are experiments on the electrolization of water. Early in the following year Sir Joseph Banks wrote to Sir George Staunton (in China): * * * * * We are going on here as usual, but I think the taste for science is on the increase. The Royal Society has been well supplied with papers, and continues to be so. Davy, our secretary, is said to be on the point of marrying a rich and handsome widow, who has fallen in love with science and marries him in order to obtain a footing in the academic groves; her name is Apreece, the daughter of Mr. Carr, who made a fortune in India, and the niece of Dr. Carr, of Northampton. If this takes place, it will give to science a kind of new éclat; we want nothing so much as the countenance of the ladies to increase our popularity. Very little laboratory work was done in 1812. It appears from Davy’s notes that a few experiments on euchlorine were made in January. In February he was again working on sulphur and phosphorus and chlorine. In March he was experimenting on borum with oxygen, and with chlorine. In August an experiment was made to ascertain whether there is, according to the received belief, a neutral part in the voltaic circle. The battery consisted of forty double plates, thus arranged: Each trough, excepting the end ones, was separately connected with a glassful of mercury by polished copper wire, and each pair of glasses was connected by very fine polished iron wire. The effects took place at the moment of contact at all the wires, so that there could have been no _neutral point_. For the last time, after innumerable failures, he returned to the decomposition of nitrogen. On August 13 ‘experiment very cautiously made of the action of potassium on nitrogene. Light green when mercury is employed, red when potassium.’ On October 23 the Laboratory Book says: ‘A series of experiments to attempt to decompose hydrofluoric acid, and to ascertain the constitution of the _fluoric combinations_. ‘1. To obtain pure hydrofluoric acid. ‘2. To obtain silicofluoric acid gas, and to decompose it by potassium and by potash, and to ascertain the quantity of fluate of lime they will give. ‘3. To make pure prussic acid. ‘4. To act upon pure prussic acid by chlorine.’ On November 5 a new detonating compound was formed; this was the chloride of nitrogen. This year Davy gave his last course of lectures on Chemical Philosophy at the Royal Institution.