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CHEMICAL NOTES OX A STONE LAMP IROM BALLYBETAGH, 

 AND OTHER SIMILAK STONE VESSELS IN THE EOYAL 

 IRISH ACADEMY COLLECTION. 



By RICHARD J. MOSS, F.LC, F.C.S. 



Bead Apkil 25. Ordered for Publication .\PEit 2". Publbhed Ji-lt 16, 1910. 



Ix the year 1875, a fanner residing at Ballybetagh, near the Scalp, on the county 

 Wicklow side, gave me a stone vessel of the .so-called chalice-tj'pe, and it has 

 been in my possession since that time. The donor Wiis unable to tell me 

 where the vessel was found ; all he knew about it was that it had been a 

 recognize*.! object of antiquarian interest in his hou-se as long as he could 

 rememlier, and that it had been in the same house in Ins father's time. 



In a paper on " Stone Chahces, so called,'" Mr. E. C. 11. Aimslroug dis- 

 cusses the proljability of vessels of this tj"pe being lamps (a view wliich it 

 appears was first suggeste*! by Mr. Geo. Coffey, of the National Museum), and 

 not cups or chalices, and comes to the conclusion, on grounds chiefly historical 

 and ethnological, that the vesseb are lamps. It occurred to me that a lamp 

 of stone, if at all porous, would be sure to contain some trace of the 

 oil or grease which had been burnt in it The Ballybetagh vessel is of 

 decidedly porous material, and therefore seemed a very suitable subject 

 for experiment. 



The Ballybetagh vessel, as represented in the accompanying photograph 

 (fig. 1, p. 163), weighs 1756 grammes, and its specific gra\-it)' is 2'19. Tliis 

 very low specific gra\-ity suggests a much-decomposed rock, and therefore a 

 high d^ree of porosity. 



I placed the veeael in a jar with about 300 cc. of ether, and after the lapse 

 of twenty-four hours removed the ether and distilled it This operation left 

 a dark-brown, grease-like residue, weighing 0092 gramme, and with a ver}' 

 distinct odour of tallow. The extraction with ether and the ilislillation were 

 repeated several times until the residual grease weighed 0*775 gramme. This 

 is only 0*04 per cent of the weight of the vessel 



' Proceoliogi o{ ike B071I Irish Acadeajr, Tui. uri., Sect. C, No. 13. 



