388 FLAME-HEAT IN THE CHEMICAL LABORATORY. 



burner, doubtless from its being either invented or brought into 

 extensive practical use by the distinguished chemist of Heidel- 

 berg. Its form is too well known to require more than a mere 

 mention here, and it is now made of all sizes, from those capable 

 of burning four cubic feet of gas and under to those which can 

 burn fifteen or twenty cubic feet from a single burner or from 

 a combination of several smaller ones. To this burner some 

 material additions have been made by different individuals. 

 J. J. Griffin (the chemical instrument dealer in London) was, 

 I believe, the first to introduce the use of the rosette and the 

 register for the supply of air. The most remarkable results 

 accomplished by this method of burning gas and air are those 

 obtained by G. Gore, of Birmingham (all of whose results I 

 have verified), where gold, copper, cast-iron, etc., were fused in 

 crucibles without the agency of any artificial blast. Mr. Gore 

 evidently realized ful]y the true principle of burning this mix- 

 ture so as to obtain a maximum effect; the burner, however, 

 with its furnace arrangements, is unavoidably of a form and on 

 a scale limiting its application. 



The usual form of the Bunsen burner, with the rosette and 

 register (when required), bids fair to hold its own against any 

 other form for general purposes, and whatever modifications 

 may be made on it should be of such a character as not to in- 

 trench on its simplicity. One or two of these modifications are 

 now in daily use in my laboratory, for which there is no claim 

 to any special originality, nor are they intended to supplant the 

 ordinary form. 



As simple an instrument as the Bunsen burner appears to 

 be, its principles and effects are well worthy of being carefully 

 studied. 



As the gas passes from the small orifices* in the lower part 

 of the burner, and mixes with the air drawn in at the lower 

 opening and passes out at the open end of the tube, it usually 

 contains not quite enough oxygen for its complete combustion, 

 and requires free access of air to the outer portion of the flame 



* The outlet for gas may be in the form of crossed slits or two small holes 

 (one thirty-second inch in diameter each) for the small-size burner, the length 

 of the tube being about four to four and a half inches ; the next larger has 

 four openings (about one twenty-fifth inch diameter each), and the tube about 

 five inches long. 



