The management of the light from the lamp, through the lens, _a_, and from the concave mirror, _b_, to the objects, is exactly the same as before directed by Mr. Adams. For the exhibiting of transparent objects, the stage, C, is to be slid away, and the body, Fig. 4, applied in its place, in that position, with the large lens outwards next the lamp. The slider with the objects passes through at _a_, and the focus for the different magnifiers is adjusted by turning the long rod, D, to the right or left, as with the opake objects. In this case the lamp is to be raised to the center of the body of the microscope, or even with the magnifiers at L. The image of the objects may also, as in Mr. Adams’s, be best received on the rough glass placed at F, for the simple reflected light through the body will sometimes be so strong, as to irritate the eye; the operator must, therefore, both modify that from the lamp, and place the roughed glass to his own ease and pleasure. The guide for the eye, N, in this instance is not necessary. Care being taken that the roughed glass at F be kept in as dark a situation as possible, there will be a certainty of a clear and well-defined view of the object. A tin chimney placed over the glass of the lamp about ten inches long, with a suitable aperture to admit the light to pass through it to the glasses, is of material service; it excludes all superfluous light from the eye of the observer, keeps the room sufficiently darkened, and enables the observer to view his object with the proper brilliancy. As a pleasing relief to the eye, the interposition of a small piece of blue or green glass at the sight hole, N, Mr. Jones has sometimes found necessary, but it gives rather a false teint to the colour of the objects. In the year 1789 the same artist applied a brass screw pillar and arm to the top of the box at O, on which is occasionally slid the condensing lens, _a_. The lamp being then applied at the side of the box at O, instead of the end, and the lens, _a_, moved to such a distance as to give the strongest possible light upon the opake objects at C; they were found to be more strongly illuminated by this simple refracted light than by the refracted and reflected light before used. Light is always somewhat diminished by reflection, although condensed; therefore, as it is sometimes best to view the objects from oblique reflected light, and sometimes from direct refracted, he constructs the apparatus so as to give the operator the means of easily using either. The dotted lines, O P, shew the manner that the glass semiglobe, _a_, is occasionally applied to refract or converge directly the light from the lamp to the objects on the stage.