Proceedings of the roLYTEcnxic Association. 8G7 



Iteliiiul, which, after a sliort stay in the meatus, ])C£^in to fenvieiit, 

 and tlius cause fresh irritation. A little pure gljx'erine nuiy be 

 added to the water, in which it is perfectly soluble. The injection 

 Siiould be made with a syrino-e having an end large enough to pre- 

 vent its penetration too far into the meatus and hurting any part. 

 Moreover, the liquid should go in ver}^ gently, so as not to give any 

 violoTit shock to the tympanum, which, should it happen to be thin, 

 wuuld run the risk of rupture. On the other hand, in order to be 

 sure that the li'.paid column will penetrate to the l)()ttom of the 

 ineatns, the latter should l)0 kept aa much as possible in a per[>en- 

 dicular position during the operation ; a precaution of double 

 importance when it is required to get any extraneous substance out 

 of the ear. Many very ingenious instruments have been invented 

 for the purpose of extracting substances from the ear, but, according 

 to the author, they are all useless when not dangerous. The method 

 he proposes is simple enough, aiid appears to answer au}^ emergency. 

 It is an extremely rare, perhaps an impossible case, that an extrane- 

 ous body should happen to fit S(j exactly in tlie meatus as completely 

 to obstruct its passage ; it generally leaves interstices, through which 

 water poured into the car must necessarily penetrate to the farther- 

 most end. !Now the liquid, so introduced, will gradually rise, and 

 exercise a pressure upon the intruder from behind, and, in a manner, 

 set it afloat. Dr. Cousin de(;lare3 he has never known an instance 

 of this sitnple method to fail; but that, on the contrary, it has suc- 

 ceeded in cases where extraction vrith instruments had been tried in 

 vain by the most dexterous hands. 



The Effect of Fkeezixg. 

 The London Daily iSTews says it is not true, as generally supj^osed, 

 that the act of freezing eliminates from water all im])ure matter. It 

 generally does extrude coloring matter, but not (u-ganic inq)urities; 

 indeed, such matters, although prevented from decomposing by the 

 cold, appear to decompose with redoubled energy immedi;itely the 

 temperature is sufficient to melt the ice which holds them. 



Adtaxtage of Powdkuki) Lime fou Mortar. 



A French engineer has made an able re])iirt on the economy of 



using lime ground to a line po\vder, instead of slaking it in lumps. 



He estimates the loss in using lunq^s at twenty-five per cent. Besides 



this saving of matei-ial it is found ;]iat lime in })owder is spread with 



