£4r ACCOUNT OF BOOKS, &C 



Speeron the its temperature, the fcale upon each of the faces is adapted ts 

 Hydrometer. a determinate temperature, namely 35°, 40°, 45°, &c. till 

 the laft, which is for 70°. The temperature of the fpirit be- 

 ing therefore known, the refult muft be read, upon that face, 

 at the top of the which the known temperature is engraved ; 

 and to prevent any miftake, there is a fmall index to be put 

 on the (iem to direct the eye of the obferver to the proper 

 face. And moreover, as the temperature is fhewn only to 

 every five degrees, there is another index of a different co- 

 lour, which performs the office of a weight, and thews the 

 intermediate temperature. This may alfo be effected by 

 warming the fpirits, by holding the glafs in the hand till its 

 temperature agrees with that marked on one of the faces ; or, 

 as I underftand from the fpecification of the author's patent, 

 the precifion of a fingle degree, if required, may alfo be ob- 

 tained, by four fmall pins to be inferted, one for each interme- 

 diate degree in holes, in the counterpoife below, where in fact 

 they operate as weights of adjuftment. 



On thelaft day of this month, Mr. Macartney will com- 

 mence a Course of Lectures in the Medical Theatrf 

 of Saint Bartholomew's Hospital, on the Anatomy of 

 Animals and Vegetables, from which will be deduced the ge- 

 neral Doctrines of Phyfiology, or the laws of Organized 

 Matter. 



For Particulars, apply to Mr. Nicholson, at the Apo- 

 thecary's Shop, St. Bartholomew's UofpitaL 



