Sir Richard Threlfall and the Automatic Microtome

Abstract

THE appreciative notices of Sir Richard Threlfall which have appeared in NATURE have made no reference to what was probably his first notable invention;—and one that revolutionised an essential method of biological research. As a contemporary of his at Cambridge, among the first who had the opportunity of profiting by his results, I may perhaps be permitted to emphasise its importance. It had been realised for some time that the structure of an animal could be studied with great advantage with the aid of a complete series of sections arranged in order on microscopical slides. Until 1883 no satisfactory method was known of preparing and mounting such a series. Each section had to be separately placed on the slide, where the material in which it had been embedded was dissolved. Parts of the section which were not connected with others floated away and were lost; and the sections already in place were disarranged, involving the necessity of readjusting many of them before the next section could be added. The work involved was extremely laborious, as I can state from personal experience, and the final result left much to be desired. These were, however, the methods with the aid of which F. M. Baliour established his reputation as an embryologist.