VOL. LXVI.j PHILOSOPHICAL TRANSACTIONS. 113 



philosopher has published as the result of his inquiry. His experiment stands 

 thus recorded (Suppl. Nat. Hist. vol. 2, p. ] 1) : a mass of iron, after receiving 

 a white heat, weighed 49 lbs. 9 oz. ; when restored again to the temperature ot 

 the atmosphere 49 lbs. 7 oz. Hence he concluded, that the igneous particles, 

 contained in the heated iron, increased its absolute weight 2 ounces. 



My experiments are as follow : 1st, 1 dwt. of gold, made red hot, became 

 apparently lighter ; but, when restored again to the temperature of the atmos- 

 phere, its former weight was perfectly restored. 2d, I dwt. of iron, heated as 

 above, was also apparently lighter ; but, when it became cool again, its weight 

 was visibly augmented. I repeated these experiments several times, and the 

 results were always the same. The beam used in these experiments was sensibly 

 affected by the ^-oW P^'"t of ^ grain ; and each of the metals was heated on char- 

 coal, by means of a candle and a blow-pipe, and both were brought nearly to a 

 state of fusion. 



It seems needless to observe, that the apparent levity of the gold and of the 

 iron, when hot, was owing to the ascent of the rarefied air above the scale, and 

 to the tendency of that underneath to restore the equilibrium of its pressure. 

 The increase of weight in the iron might probably arise from its having, in 

 some degree, acquired the property of steel, by means of the flame and charcoal. 

 I am at a loss to account for the fallacy which seems to have attended 

 M. BufPm's expeiiment ; but it seems probable, that the heat of the mass of 

 iron employed by him, had a greater effect on that arm of the beam from which 

 it hung than on the other ; which, being less heated, would consequently be 

 less expanded ; and this difference of expansion might produce the error in his 

 account of the weight of heated iron. 



XXXIX. An Account of a Suppression of Urine cured by a Puncture made in 



the Bladder through the Anus. By Dr. Robert Hamilton, M. D., of King's- 



Lynn, Norfolk, p. 578. 



The subject of this history had laboured under a suppression of urine for 3 

 days. The treatment usual in such cases had been adopted without success, and 

 attempts had been made to introduce catheters of various sizes, but all in vain. 

 The bladder was distended to an enormous size ; the pulse was small and 

 quick ; hiccup had come on, and he had vomited every thing he had swallowed 

 from the 1st day of his illness. In this extremity, Dr. H. resolved on puncturing 

 the bladder, as the only chance of saving the patient. While Dr. H. was con- 

 sidering which would be the best mode of performing the operation, the mother 

 of the patient told him that she had several times that day attempted to give him 

 a clyster, but had not been able to introduce the pijje, by reason of a large sub- 

 stance low in the gut near the fundament, which stopped up the passage. It 



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