Abstract
In 1846 the Belgian scientist François Donny published a very important but still virtually unknown paper. Apparently the first publication on the ability of liquids to withstand tension, it appeared some four years before Marcelin Berthelot's famous paper on this property of liquids. It seems only fair to record the fact that, contrary to accepted belief, Donny, not Berthelot, was really the first pioneer in this field. In his paper Donny describes how he first observed by chance the fact that a column of sulphuric acid in a manometer could sustain a small tension. This led him to investigate the matter further, and he found that a column of this acid could stand a tension of about a quarter of an atmosphere. From later experiments he concluded that a column of water could sustain at least one atmosphere of tension. The work described in Donny's paper is discussed and compared with the related work of Marcelin Berthelot and Osborne Reynolds which was published later in the nineteenth century. The relevance of this to current research work is also discussed briefly