Scientific Intelligence^ ^c. 75 



and Bergman had previously considered ice a conductor, although 

 afterwards the latter with Achard and Ermann confirmed the accuracy 

 of Franklin. The remark of Faraday, that the *"' assumption of 

 conducting power by bodies as soon as they pass from the solid to the 

 liquid state, offers a new and extraordinary character, the existence 

 of which, as far as I know, has not before been suspected," is super- 

 seded by the experience of Franklin related in a letter to Cadwalla- 

 der Coiden of New York, dated April 23rd, 1752. " I do not 

 remember," says he, '' any experiment by which it appeared that 

 highly rectified spirit will not conduct : perhaps you have made such. 

 This I know, that wax, rosin, brimstone, and even glass, commonly 

 reputed electrics per se, will, when in a fluid state, conduct pretty 

 well — glass will do it when only red hot." Again, "a certain 

 quantity of heat will make some bodies good conductors that will not 

 otherwise conduct. Thus wax rendered fluid and glass softened by 

 heat, will both of them conduct. And water, though naturally a 

 good conductor, will not conduct well when frozen into ice." 



VIII. — Residuum of Fired Gunpowder. 



Lieut. Braddock has examined the residue remaining after the 

 explosion of gunpowder. The specimen examined was obtained 

 from the Madras powder mills, and was collected from an 8 inch 

 iron mortar after firing off two ounce charges : the composition of 

 the powder being, saltpetre, 75, charcoal, 13^, sulphur 11-|. The 

 constituents of the residue were, sulphate of potash, 46*83, carbonate 

 of potash, 26*73, nitrate of potash, 15*34, sulphuret of potassium, 

 6*65, sulphuretted hydrogen, 1*52, unconsumed charcoal, 6*60, and 

 earthy matter 2. — Madras Journal of Literature and Science^ 

 Jan., 1836. 



IX. — Creosote as an Antiseptic. 



HuNEFELD has ascertained that the addition of a small quantity of 

 creosote not only prevents solutions of sugar and pastes from fer- 

 menting, (10 to 15 days in June,) but likewise reserves healthy 

 and diabetec urine, in corked vessels, completely unchanged. Hence 

 it may be inferred that the presence of smoke in the neighbourhood 

 of a fermenting tun will be prejudicial to the operations of the 

 brewer. — Pharmac. Centralblatt, May 1836. 



X. —Lithotrity employed in Persia in Ancient Times. 



In the Khamas and Hadschar, an Arabic medical work, whose date 

 is unknown, under the description of the diamond, is the following 

 sentence : '' One of its properties is that of its grinding down stones 

 in the bladder in the following way : a diamond of the size of a 

 grain of corn is surrounded with a cover of copper, and fastened with 

 mastic or lack ; this is brought in contact with the stone and rubbed 

 against it until it is broken to pieces, and the small portions dis- 

 charged with the urine." — Brandes' Pliarmac. Zeitunq, No. 4, 

 1835. 



