120 



due charred, digested in nitric acid, and the acid solution filtered 

 and exposed to a stream of sulphuretted hydrogen. A dark precipi- 

 tate was obtained which was dissolved in dilute nitric acid, evapo- 

 rated to dryness and redissolved in water, acidulated with hydro- 

 chloric acid. This solution was tested with sulphuretted hydrogen, 

 sulphuric acid, iodide of potassium, and bichromate of potass, and 

 acted characteristically with all the tests. The spleen yielded the 

 fullest indications of the presence of lead, the liver came next in 

 shewing indications of the metal, then the lungs, afterwards the kid- 

 neys, and lowest of all, the intestinal canal. 



It would thus appear, that, in the case under notice, the spleen and 

 not the liver was the organ in which lead occurred most abundantly. 

 The author, accordingly, suggests that the spleen rather than the liver 

 should be the organ subjected to analysis in cases of suspected slow 

 poisoning with lead; at least, where a single organ only is analysed. 



3. Notice regarding the occurrence of Pumice in the Island 

 of Tyree. By The Duke of Argyll. 



The Duke of Argyll (in connection with other evidences of a more 

 conclusive kind, that, during some portion of the tertiary ages, there 

 had been some subaerial volcanic action in the Hebrides) explained 

 the mode in which pumice occurred in the Island of Tyree. The 

 pumice was found to form a bed or layer along the line of an ancient 

 sea-beach, and was in the shape of balls more or less closely packed 

 together. These appearances seemed to indicate that they had come 

 in on the waters of a tide or current in large numbers at a time. 

 They were manifestly sea-borne; and the only question was as to 

 the most probable source. The bay and general line of coast on 

 which they are found is not that which is opposed to the modern 

 current of the Gulf Stream ; but, on the contrary, looks eastward, 

 that is to say, towards the trap Islands of Mull, Staffa, &c. 



The author considered it improbable that the origin of the pumice 

 could have been very distant, inasmuch as the greater the distance, 

 the greater would be the dispersion of such light floating bodies by 

 winds and currents ; and it was difficult to suppose that either from 

 the West Indies or from Iceland, pumice could have concentrated in 

 such quantities on such a spot. Its presence, however, and its de- 

 position, in the manner described, could be easily accounted for, if 



