VOL. LI.] PHILOSOPHICAL TRANSACTIONS. 41^ 



while a scale with weights was put to the other, they could raise 1 7 oz. before 

 the stockings separated. They then repeated one or two of those experiments 

 with some little variation of circumstances. They turned one of the stockings 

 inside out, and put that within the other; the inner or rough sides of the stock- 

 ings being thus together, by which means they took faster hold of each other ; 

 and they now found, that it required the weight of 20 oz. to separate them. 

 When the stockings were separated, and applied externally to each other, they 

 then raised the weight of 10 oz. 



They next proceeded to try the force of electrical cohesion with the stockings 

 of a more substantial make, viz. those above described; and there they found it 

 to be much more considerable, as appears by the following experiments. 



lO. — When the white stocking was put within the black (without either of 

 them being turned inside out) so that the outside of the white was contiguous 

 to the inside of the black, they lifted g lb. wanting a few pennyweights. Now, 

 taking the weight of the stocking to be 1 oz. 18 dwt. 15 gr. viz. the half of the 

 weight of the pair as mentioned above, it follows that, by the force of its cohe- 

 sion with the black, it raised 55 times its own weight. 



2,0. — When the white was turned inside out, and put within the black, their 

 inner or rough sides being contiguous, they lifted no less than 15 lb. l^dwt. 

 before they separated: so that, in this case, the single stocking raised 92 times 

 its own weight. 



30^ — ^When the inner stocking was drawn out, and applied to the outside of 

 the other, they lifted Hlb.; that is, between 10 and 1 1 times the weight of the 

 white stocking. 



XXXVII. Some Observations relating to the Lyncurium of the Ancients. By 

 miliam Watson, M. /)., F. R. S. p. 394. 



To determine the substance, denominated lyncurium by the ancients, has been 

 the occasion of much controversy among the more modern naturalists; some of 

 whom, as the late Dr. Woodward, believed it to be a species of belemnites; 

 others, as the late M. GeofFroy, considered it as amber. But it is evident from 

 Theophrastus's description of the lyncurium, which is the most complete that is 

 come down to us, that neither the one nor the other of the beforementioned 

 substances could be what he intended. His words are, Kat to Xvynsftov. xai yap sa 



T8T8 'yXu(p£Tai TO, (Tipixyi^nx.. y.oci £?Ti ;T£p£WT«Tri, >ca9a7r£p A»Soj, £A)tfi yap uKTm^ ro nAfJtT^ov, 

 cl ^t (poic-iv 2J uovoi/ y.a,p(pri xai ^uAov, aAAa )c«i p^aAxoi/ xai ci^Jipoi/, txy r, A£7rTo?. (txnvif xai 

 Aio)cA»if £A£y£v. ''E?Ti Si ^ioc(pxvr\g n (T(poSp(X, y.xl Trupp'a yivtrxi $i xa; xaTEpyacria rif 



a-jTH ttAe/wi/. Hence we learn, that " the lyncurium was a stone used for en- 

 graving seals on ; that it was very hard ; that it was endowed with an attracting 



3h2 



