VOL. L.J PHILOSOPHICAL TRANSACTIONS. 123 



M. Simpson, of Pencaitland, who had been afflicted with symptoms of gravel 

 and stone, by the daily use of soap, taken in the form of pills, which he first 

 took in doses of a drachm a day, but afterwards increassed to the quantity of 5 

 or 6 drachms in 24 hours ; and then diminished the dose again to 4- oz. per diem. 

 In this manner he persisted in the use of the soap-pills for about 1 7 years, and 

 at length died of a diarrhoea in 1756, in the 83d year of his age. His body 

 was opened ; but no stone or gravel was found in the bladder, which appeared 

 to be in a natural state, except at the neck, where the coats seemed to be 

 scirrhous, and were about ^ of an inch thick. It is supposed the stone, 

 which previously existed in the bladder, as had been ascertained by the catheter 

 in 1735, was of a soft texture, and had been dissolved by the soap. 



A Letter from Dr. Adam Drummond to Dr. Adam Austin^ relating to the 

 Rev. Matthew Simpsons Case. Communicated by J. Pr ingle, M. D., F. R. S. 

 p. 226. 



In this letter it is stated by Dr. D. that he was present when Mr. Balder- 

 stone sounded Mr. Simpson, and that both of them perceived, very distinctly, a 

 large stone; that Mr. Simpson himself felt it; which they were the more soli- 

 citous he should do, as he had been sounded before by Dr. Simpson, who had 

 declared there was no stone. But the particular magnitude of the stone they 

 could not well determine at the end of a large catheter ; though he remembered 

 Mr. Balderstone, who was well versed in that business, conjectured it to be pretty- 

 large. 



XXVJII. On the Impressions of Plants on the Slates of Coals. By Mr. 

 Emanuel Mendes da Costa, F.R.S. p. 228. 



The impressions of various kinds of plants are frequently, Mr. C. thinks al- 

 ways, found in some of the strata lying over coal ; bat more particularly in a 

 stratum of earthy slat, which always lies immediately on the coal-stratum, not 

 only in the coal-pits of this kingdom, but of many other parts of Europe, as 

 France, Saxony, Bohemia, Silesia, &c. Most of these impressions are of the 

 herbae capillares et affines, the gramineous, and the reed tribes ; but among them 

 are many rare and beautiful impressions undoubtedly of vegetable origin, and 

 impressed by plants hitherto unknown to botanists. Besides these found over 

 coal-pits, there are likewise found in some parts of this kingdom, as at Robin- 

 hood's-bay in Yorkshire, Coalbrookdale in Shropshire, &c. many curious im- 

 pressions of the fern tribe in regular nodules of iron-stone ; and, in the latter 

 place, not only impressions of plants, but even the cones or iuli of some kinas 

 of trees are met with, very perfect and fair, and curiously imbedded in masses of 



iron-stone. 



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