'Sir Humphry Davy, in the year 1825, originated the Zoological Society, and asked me to join, which I did most willingly; and perhaps it has been the most popular and successful of any modern society of that kind. It commenced operations by purchasing the well-known Cross collection of Exeter 'Change, in which, in my early days, I took an especial delight; for, considering all things, it was a very wonderful collection, and it is difficult to understand how, in such a confined and unhealthy spot, it could have been maintained in such good condition. The only other exhibition of the kind in London was at the Tower; the collection of animals there consisted of presents from the sovereigns of different countries. These were afterwards lent to the Zoological Society, who established their museum in the Regent's Park; and taking it altogether, it is probably the finest and best maintained in the world.' In the spring of 1815 he returned to England, _viâ_ Mayence and Brussels, and bought for his residence a house in Lower Grosvenor Street, No. 28. There is perhaps no subject connected with the career of Davy with which his name is more inseparably and more honourably associated than that now to be mentioned,--and it was a subject which even the genius of a Humboldt had failed to master--namely, the brilliant and philanthropical discovery of the Safety Lamp (the original lamp in its first and simplest form is preserved in the Royal Institution), which has often been described in detail. His brother goes fully into the train of reasoning and of experiments which led to its construction. It is, as he says, a cage of wire-gauze which actually makes prisoner the flame of the deadly fire-damp, and in its prison consumes it. This grand invention--and it is not the less grand because it is so simple--by which in all probability more lives have been saved than by any other invention of similar character,--Davy nobly refused to patent, lest the sphere of its usefulness should be restricted: indeed, throughout his life he was indifferent to mere money; he was constantly giving away things for which he had no immediate use, and never kept a book after he had once read it. He received for the invention of the Safety Lamp unbounded praise and heartiest thanks from the great body of coal-owners and coal-workers of the Tyne and Wear especially; and was presented by them, on 11th October, 1817, with a magnificent service of plate worth £2,500,[111] at a public dinner at the Queen's Head Hotel, Newcastle, when the Earl of Durham (then Mr. Lambton) said in the course of his speech: 'If your fame had needed anything to make it immortal, this discovery alone would have carried it down to future ages, and connected it with benefits and blessings.'