“The following list of lantern slides includes all of the photographs made during the past six years by Dr J. Leon Williams in his studies of the microscopic morphology and pathology of enamel. Dr Williams has repeatedly been urged to undertake the preparation of text books based upon the above-mentioned studies, but the uncertain condition of his health (which was seriously injured by too close application to photo-micrographic work), and the demands of a large practice make it improbable that he will ever undertake the preparation of text books.

We believe the photo-micrographic work of Dr Williams has everywhere been recognised as the finest that has ever been done in this field, and it probably is not claiming too much to say that many of these photographs will not be duplicated for many years. Believing that most of the dental colleges throughout the world will be glad to avail themselves of the opportunity to secure these fine photographs, we have secured from Dr Williams all of the original negatives and the accompanying explanatory list which he has prepared.

In addition to the above-mentioned slides there is also a supplementary list on the bacteriology of the human mouth. This list deals more especially with the various forms of micro-organisms resulting from the fructification of Leptothrix vacemosa. This organism, which was first discovered by Dr Vicentini, of Italy, was also independently discovered by Dr Williams, and up to the present time he is the only one who has succeeded in photographing it. Experts have pronounced these pictures some of the finest work that has ever been done in photo-micrography.”