360 Miscellaneous Intelligence. 



This ointment is now undergoing extensive trial, and the re- 

 sults are very favourable. Already several testimonies have 

 been given by medical men to its value. 



2. Method of preparing Extracts. — Mr. Barry has lately taken 

 out a patent for the preparation of extracts by evaporation in 

 vacuo. The evaporating pan, of polished iron, is converted into 

 a still, by being closed at top, and its beak, or pipe, is led 

 away to a copper sphere, which is the condenser : the con- 

 nexion between the two being made, or closed, by a stop-cock. 

 Both the still and the condenser are placed in vessels intended 

 to hold water; the first being a water bath, the second a refrige- 

 ratory. The juice, or infusion, being introduced into the still, 

 and all perfectly closed, water is poured into the vessel contain- 

 ing it until the still is covered ; then the cock between it and the 

 condenser being shut, steam is thrown into the condenser until 

 all the air is expelled ; the cocks are then closed, and cold water 

 being poured on, a vacuum is produced ; the connexion is then 

 opened between the condenser and the still, and the former being 

 four times the capacity of the latter, a considerable exhaustion 

 is produced in it ; the cock is then closed, steam is again sent 

 into the condenser, and the exhaustion made as before ; and 

 this is repeated four or five times, until the barometer gauge at- 

 tached rises to about twenty-eight or twenty-nine inches ; steam 

 is then introduced into the water bath, and the still heated, and 

 the condenser being kept cool, rapid ebullition goes on at a 

 temperature little above 95°. There is a barometer gauge to 

 ascertain the exhaustion, a thermometer in the still-head for the 

 heat, and also a strong glass window in it to shew the state of 

 things within. Tlie action of this apparatus is so perfect, that 

 the height of the mercury is frequently twenty-eight inches dur- 

 ing rapid ebullition ; and it is an usual thing to work with it at a 

 height not two inches less than the barometer of the day. Ex- 

 tracts prepared in this way, appear considerably different 

 from common extracts, and, in some cases, uiu. h stronger. 

 It, however, will require some time before all tlie advantages 

 of the apparatus, or the medicines prepared by i*, can be 

 known. 



