SD6 Scientific Intelligence' [May, 



described may be readily conceived ; for it is evident that the 

 suction, or demand for aix at c, would be proportioned to the blast 

 that issued from the orifice at n. 



" The dimensions of such parts of the apparatus described in 

 the Philosophic;d Transactions as relate to the present purpose, 

 were the following: height of the funnel 5 feet; diameter of the 

 throat of the funnel 3 l inches ; diameter of the bore of the pipe b 

 5-i- inches; length of the pipe /', 14, 15, or 16 feet; diameter of 

 the air holes at its upper part (two in number) 1-i- inch. An engine 

 of these dimensions is said to have afforded, through a hole at n, 

 \\ incl) in diameter, a blast of sufficient power " to smelt ore harder 

 than any in Leadhills." 



IV. Meaning of the French Word Genie. 



I am obliged to an anonymous correspondent, who subscribes 

 himself N. N. for the following explanation of the French word 

 genie^ which !■ left untranslated in the Biographical Accounts- of 

 Lowitz and Malus because I did not know its correct meaning. 



^ Give me leave to set you right on the subject of the French 

 word * genie,' as used in \he Annals of Philosophy, vol. iii. page 

 17I) and pages 241 and 243. 



" The Dictionary of the French Academy, after having given 

 the other significations of the word, adds : 



* Genie, est aussi I'art de fortifier, d'attaqucr, de doicndre une 

 place, un camp, un poste.' — ' II s'est mis dans le genie.' — ' 11 est 

 ilans le genie depuis trois ans.' — ' Le corps du gtnie, the corps of 

 military engineers.' — ' Ofhcier du genie.' — ' liigeitieur, an officer 

 of engineers.' — ' Major du gc'nie, a major of engineers.' — ' Inge- 

 nieur militaire.' — ' Officier de genie militaire,' is used in contra- 

 distinction of ' ingenicur des ponts et chausses,' i. e. a civil engi- 

 neer and surveyor." 



London, lOth April, 1814. 



V. Ventilation of Coal Mines. » 



In consequence of the publication of Mr. Taylor's paper on thl» 

 subject in a preceding Number of the Annals of Philosophy, I 

 have been favoured with a visit from Mr. Wilson, who is the pa- 

 tentee of a new pump seemingly constructed upon very ingenious 

 principles. He suggests the application of this pump to coal 

 mines, and says that it will draw out 4000 gallons of air in a 

 minute. 



VI. Method of destroying the Insect that injures Apple Trees. 



(To Dr. ThomEon.) 

 •SIR, 



In reply to your correspondent's query of last month respecting 



the most effectual mode of destr()yii)g the aphis on apple trees, I 



beg leave to acquaint you with the method 1 have practised for 



some years with complete succcis. As soon as the insect makes its 



