form of insanity which consisted in his believing that the posterior portion of his body was made of glass!
In support of all this farrago of nonsense there is of course no foundation of truth; Robison was a well-known savant who lived sane and respected to the end of his days. On his death Watt wrote of him: "He was a man of the clearest head and the most science of anybody I have ever known." John Playfair, in a paper read before the Royal Society of Edinburgh in 1815, whilst criticizing his Proofs of a Conspiracy--though at the same time admitting he had himself never had access to the documents Robison had consulted!--paid the following tribute to his character and erudition:
His range in science was most extensive; he was familiar with the whole circle of the accurate sciences.... Nothing can add to the esteem which they [i.e. "those who were personally acquainted with him"] felt for his talents and worth or to the respect in which they now hold his memory.<sup></sup>
Nevertheless, the lies circulated