92 Roijal Society, 



the l^ark was. On the other hand, many trees with bark 

 very shnilar, have wood very different. These facts, in con- 

 junction with some minute expcTiments, Mr. Knight con- 

 cluded as decisive that the hark is not transmuted, as MaU 

 pighi supposed, into alburnum ; but that each performs its 

 peculiar function in the ceconomy of vegetation. 



February 11 and 18. Several mathematical papers on 

 the properties of a circle, Slc , were presented to the Society 

 fcy the astronomer royal, but were not of a nature to be 

 read. A curious paper on cranites^ or the idiotism of the 

 inhabitants of alpine regions, who are affected with goitres, 

 or swellings about the head, was read. From the author's 

 researches among the people of Switzerland, and his inves- 

 tigation of the supposed connection between this species of 

 mental imbecility and. goitres, (which are generally ascribed 

 la the effect of using snow-wa,ter on the glands,) he was led 

 to conclude that cranites exists frequently where there are no 

 goitres, and that many families suffer the latter complaint 

 without experiencing the former. 



February 25. A. Marsden, esq-., in the chair. A ge- 

 ological paper on the whin-dykes in the north of Ireland, 

 in a letter to Mr. Davy, was laid before the Society. 



A continuation of Mr. Home's experiments on the func- 

 tions of the spleen was read, in which this able naturalist 

 operated on asses with extract and tincture of rhubarb, as 

 related in his former experiments on dogs. The spleen and 

 the colon were found impregnated with the rhubarb, when 

 none was found in the liver. Several curious experiments 

 were made to ascertain the quantity of serum and of rhubarb 

 found in the blood in the vena cava, the left auricle of the 

 heart, and other members : but the results are not satis^ 

 factorily established. /orjin-'M; 



A letter from Mr. Mutdoch, to the president, was read, 

 containing an account of the origin, progress, and present 

 irtate of gas-lights. It appears that so long ago as 1739 

 Dr. Clayton, in the Philosophical Transactions, discovered 

 the inflammability of gas procured from coals : but this 

 knowledge was never adapted to practice till about sixteen 

 years ago, when the author, at a foundry in Cornwall, first 

 •\^\ proposed 



