18 de Setembro
The Daguerreotype. – One great obstacle to the use of M. Daguerre's photegenic process is the difficulty of preserving the pictures when completed, because they are of so delicate a nature, and so easily injured, that tho slightest touch effaces them; even M. Daguerre himself as always found it necessary to protect them with a plate of glas, which is both inconvenient and troublesome; and it has, in consequence, been suggested, that if a varnish could be discovered, which might easily be applied to the surface of the plates after the completion of the pictures, and which, while it protected them from injury, should not impair their delicacy, it would considerably add to the value and use-fulness of the process; we are happy, therefore, to hear, that M. Dumas has discovered that a liquid, composed of one part of dextrine and five parts of water, forms a varnish of the desired nature. It is said to be well adapted for the purpose, and further possesses the advantage of being easily removed from the surface of the picutre, by immersing the whole in boiling water. Time, however, will be required to ascertain whether this varnish has any action on the peculiar mercurial compound of which the image is formed. - Ataenœum.