Microscope Glasses (To Clean). When you clean the eye-glasses, do not remove more than one at a time, and be sure to replace it before you begin another; by this means you will be sure to preserve the component glasses in their proper places; recollect that if they become intermingled, they will be useless. Keep a piece of well-dusted chamois leather, slightly impregnated with some of the finest putty or crocus powder, in a little box to wipe them with - for it is of consequence to preserve it from dust and damp; the former will scratch the glasses, and the latter will prevent you from wiping them clean. As to the object-glasses, endeavour to keep them as clean as possible without wiping, and merely use a camel's-hair pencil to brush them with; for wiping them hard with anything has always a tendency to destroy their adjustment, unless they are firmly burnished into their cells (see Microscope, p 80).