My friend, Mr. Rylands, successfully mounts the diatoms in the state in which he finds them, and gave me the following method as that which he always employs. He says that he has had no failures, and hitherto has found his specimens unchanged. Take a shallow ring cell of asphalt or black varnish (which must be at least three weeks old), and on the cell, whilst revolving, add a ring of benzole and gold-size mixed in equal proportions. In a minute or two pure distilled water is put in the cell until the surface is slightly convex. The object having been already floated on to the cover (the vessel used for this purpose being an ordinary indian-ink palette), is now inverted and laid carefully upon the water in the cell. By these means the object may be laid down without being removed. The superfluous moisture must not be ejected by pressure, but a wetted camel-hair pencil, the size made in an ordinary quill, being partially dried by drawing through the lips, must be used repeatedly to absorb it, which the pencil will draw by capillary attraction as it is very slowly turned round. When the cover comes in contact with the benzole and gold-size ring, there is no longer any fear of the object being removed, and a slight pressure with the end of the cedar stick of the pencil will render the adhesion complete, and cement the cover closely and firmly to the cell. When dry, an outer ring of asphalt makes the mounting neat and complete. The _Fungi_ have been before mentioned; but it may be here stated that some few of the minute forms are best preserved in a very shallow cell of liquid. For this purpose creosote-water may be advantageously used. The _antennæ_ of insects have been before noticed as being very beautiful when mounted in balsam. This is readily accomplished when they are large; but those of the most minute insects are much more difficult to deal with, and are less liable to injury when put up in fluid. _Goadby’s Fluid_ serves this purpose very well; but, of course, the object must be thoroughly steeped in the liquid before it is mounted, for a longer or shorter time according to the thickness. The _eggs of insects_ afford some worthy objects for the microscope, amongst which may be mentioned those of the common cabbage butterflies (small and great), the meadow-brown, the puss-moth, the tortoiseshell butterfly, the bug, the cow-dung fly, &c. These, however, shrivel up on becoming dry, and must, therefore, be preserved in some of the fluids before mentioned. To accomplish this no particular directions are required; but the soaking in the liquid about to be employed, &c., must be attended to as with other objects.