58 Analyses of Books. [Jan. 



single point; of a self-acting blowpipe, the old aeolipile, not 

 worth one farthing ; of a blowpipe with a self-adjusting candle- 

 stick (a self-adjusting fiddlestick to Mr. Francois Cramer's 

 violin would be about as necessary or useful) ; and a blowpipe, 

 with a stop-cock, to be used with a bladder. 



The article annexed to blowpipe (Bergman's) is made up of the 

 substance of the observations found in the best works on the 

 subject, and is culled from Bergman's Treatise, De Tubo Ferru- 

 rainatorio, Berzelius's Essai de I'emploi du Chaliimeau,&c. Our 

 author tells us, that "The best kind ofjiame for blowing through 

 with the blowpipe, is a thick wax or tallow candle." This is 

 new to us ; we did not before know that a candle and its flame 

 are the same thing ; but however that may be, we think the 

 recommendation erroneous, and prefer a low lamp, supplied 

 with oil, to any candle whether of wax or tallow ; for the lamp 

 wants no snuffing ; the wick, when once well trimmed, will last a 

 long time without requiring the least alteration, and we avoid the 

 abominable nuisance of having our hands or instruments smeared 

 with melted wax, or " stinking tallow." The advantage also of 

 being able to adapt the size of the wick to the nature of the 

 operation, is materially in favour of the use of the lamp in prefer- 

 ence to a candle. 



" In using the blowpipe, the following observations should be 

 attended to. The end of the nozzle pipe must be just entered 

 into the flame, and the current of air will then throw out a cone 

 or dart of flame from the opposite side. If it is well managed, 

 this dart or cone will be very distinct and well defined. Care 

 must be taken that the stream of air does not strike against any 

 part of the wick, as it would then be disturbed and split into 

 several parts. The jet or blast of air must be delivered some- 

 what above the wick ; and as unless the flame was considerable 

 there will not be sufticient for the stream of air to act upon, for 

 this reason the wick is best to be opened, because it then 

 exposes the largest surface, and produces the greatest flame ; 

 the stream of air from the pipe should then be directed through 

 the channel or opening between the wick, so as to produce a 

 cone the most perfect and briUiant, directed downwards at an 

 angle of about 45 degrees." 



These directions are not amiss, but require some qualifica- 

 tions. The position of the nozzle of the blowpipe v.'ith respect 

 to the flame must depend on the effect required ; if an oxidating 

 flame be wanted, the extremity of the blowpipe should be 

 inserted to some distance in the flame ; for a reducing flame, it 

 must be drawn further back, and as to the form of the wick, except 

 in cases where a large flame is required, it is best to let it be 

 cylindrical and unljroken. The flame of a wick of this form 

 will be found the most convenient and manageable in all deli- 

 cate experiments. 



