56 A MANUAL OF BACTERIOLOGY 



glass rod is softened in the Bunsen or blowpipe flame, 

 and about J in. of the platinum wire is embedded in it 

 with a forceps, the wire having been first heated to a 

 red heat. The glass-wire joint is then well annealed in 

 the flame and allowed to cool slowly. Two thicknesses 

 of platinum wire are desirable, viz. 0-4 mm. (27-30 

 B.W.G.) for most purposes, but a thicker wire of about 

 0-7 mm. where stiffness is required, and one or two 3 in. 

 or more in length are useful. 



Iron wire may be substituted for platinum wire, and 

 needles formed of it are quite serviceable. The wire 

 cannot, however, be sealed into glass rod, but may be 

 sealed into glass tubing. Metal holders with screw 

 sockets for the wires are also obtainable and aluminium 

 knitting needles make excellent holders if drilled or split 

 to receive the wire and the end then fused in the blow- 

 pipe flame. Wire made of nickel or of certain steel alloys 

 may also be used. 



Forceps, needles, etc. Several forceps are necessary, 

 the ordinary dissecting form in two or three sizes, one 

 or two pairs of fine pointed, two or three small brass ones, 

 and two or three pairs of the " Cornet " pattern. A few 

 ordinary sewing needles of various sizes mounted in 

 wooden handles serve all purposes. 



Glass pipettes and capillary tubes. These are useful for 

 preserving or storing blood or pus, etc., for examination, 

 for sterile water in making film specimens, and for many 

 other purposes. For cutting glass tubing a glass-cutting 

 knife is best, or a fine file may be used. 1 A blowpipe 

 worked by a foot bellows is desirable for making pipettes, 

 etc., though much can be done with a Bunsen burner ; 

 and if this be provided with a by-pass so much the better, 

 as the small white flame is useful for some purposes. For 



1 For the manipulation of glass, etc., see Technique of the Teat and Capillary 

 Glass Tube. A. E. Wright. (Constable & Co., 1912.) 



