On several occasions I have had the opportunity for demonstrating with the microscope additions made to certain documents, two of which were wills (testaments); these additions were made in the following manner:--First an erasure was made and then the additional matter written over the erasure. With the microscope I could at once detect the erasure beneath the addition; also the different colors of the inks. Then, and this is the most important result of the microscopical examination, by close observation, I could discern the strokes of the pen in the original lettering as well as those of the additional lettering, and finally the general mode of their execution. In regard to the examination of legal documents, United States currency, printed and written matter, mutilated documents, including forgeries, etc., from a legal point of view (as to their genuineness), it will suffice to say that the principal features are, as already stated, first, the detection of erasures and additions; second, the comparison of the colors of the different inks used in the original and in the additional lettering, and finally the mode of their execution. This includes of course a careful observation of the original writing as to the general and comparative expression. In the observation of the characteristics of the letters constituting the document, I will call attention especially to the shading and general formation of the letters, that is, the stroke of the pen either in a downward or upward movement. This comparison includes both capital and small letters and even punctuation. All these things, as well as the grammatical and orthographical relationship and comparative differentiations, must be taken into consideration in order to enable the microscopical examiner to give a positive opinion. A microscopical examination of paper documents, such as wills, notes, checks, etc., as to whether or not they have been mutilated or forged, is certainly the most reliable test, and by far the easiest and simplest method of determining the authenticity or spuriousness of a document. An expert microscopist and observer can at once arrive at a correct and positive conclusion as to the genuineness of an autograph.