Jo LY — On the Local Apj)lication of Radium in Therapeutics. 295 



The capillary tube is drawn out in one length, sufficient to make the 

 number of separate capillaries required. Into this tube the purified eman- 

 ation is brought in the usual manner. The whole tube is then sealed ofF. 

 This operation is best performed by means of radiation from a short length 

 of platinum wire, twisted into a spiral a couple of millimetres in diameter, 

 and heated by a current while it surrounds tlie tube. This simple apparatus, 

 mounted on a wooden handle, can be easily made. The advantage of this 

 mode of sealing is that there is a perfectly clean closure made ; the tube 

 collapsing under the external pressure, without forming either a drawn-out 

 thread or a bent termination which might refuse to enter the needle. The 

 capillary may be broken off at the flattened closure without risk. 



The long capillary, sealed at both ends, and containing the emanation 

 diffused through its length, is hung in a small apparatus consisting of a 

 number of platinum spirals placed one vertically above the other, and 

 adjustable as to the distance separating them. This adjustment determines 

 the lengths of the sections into which it is intended to subdivide the tube. 

 A guide plate perforated with a small hole placed above each spiral prevents 

 the glass capillary from touching the heated platinum. 



When the long capillary is so hung as to pass through the several spirals, 

 a current, sufficient to heat the spirals to full red, is switched on. In about 

 thirty seconds the sealing is completed and the tube may be lifted out and 

 broken into the small lengths intended for the needles. The simultaneous 

 subdivision of the tube effected by this means secures that the charge is 

 uniformly subdivided, and not driven by unequal heating from one part of 

 the tube to another. 



This will be found a very expeditious and simple process. The use of 

 fine capil laries to hold the emanation does not limit unduly the strength of the 

 charge. Thus the volume of emanation in equilibrium with a gramme of 

 radium — that is 1000 mJllicuries — is but 0-5 cub. mm. While, then, we can 

 load a needle with any required charge, we can also deal with partly spent 

 charges more conveniently tlian by any other method. By using a needle of 

 somewhat larger bore, and inserting two or more spent capillaries, a charge 

 may be provided liaviug tlie full value sought for : or, of course, the number 

 of needles in application may be increased as the charge decays. 



If strong charges and heavy screening are deemed preferable in any special 



case, the needle still furnishes the best form of applicator ; for lead tubing of 



any required bore is easily procured, and may be slipped over the needle, 



furnishing a screened tube of comparatively small diametral dimensions. 



I have in these remarks used the term ' illumination ' as expressing the 



