166 Transactions of the Society. 



more open end being capped with about an inch of indi a rubber 

 tubing, whipped on to make the joint air-tight, and the free end 

 closed by a clump or plug or by any other means. 



The pipette thus made is passed through a cork, so that the 

 fine opening formed at the pointed end shall reach the bottom of 

 the bottle or nearly so, and will therefore be beneath the surface of 

 the phosphorus. 



The indiarubber tube being squeezed, forces out some of the 

 air contained in the pipette, and on relaxation of the pressure, the 

 partial vacuum thus formed is occupied by a drop or perhaps two 

 of the phosphorus. 



The line point of the pipette, which will generally be found 

 free from any adhering phosphorus, is now introduced beneath, or 

 close to, the edge of the tilted cover. The tube is squeezed, and 

 the phosphorus thus forced beneath the cover instantly fills up the 

 space between it and the slide. It will not fail to be observed 

 that the whole aim has been to expose the minimum surface of 

 phosphorus to the oxygen of the atmosphere ; if phosphoric acid is 

 formed, either by fuming and condensation on the thin cover, or on 

 the exposed surface of the phosphorus the object will, as previously 

 stated, be spoilt. Should this operation have been successfully 

 accomplished — and there is no difficulty in doing it — all risk is 

 over ; the cover is gently pressed down and the mount closed by 

 passing ^some of the warm preparation of glue around it. 



When this has set pretty securely, which will be in about half 

 an hour, it will probably be found that some of the redundant 

 phosphorus has escaped from beneath the cover ; this is con- 

 veniently removed by a piece of blotting paper wetted with 

 bisulphide of carbon ; it must be applied with a pair of forceps, 

 special care being taken not to touch the paper so used with the 

 fingers, and it must be plunged into water immediately after using, 

 as it will otherwise take fire spontaneously, at ordinary tempera- 

 tures, in the course of a minute or two. Phosphorus left in contact 

 with glass does not appear to do this ; at the same time it must 

 not be forgotten that noxious fumes are always given off by 

 phosphorus when exposed to the air, and it ought therefore to be 

 removed. 



As it is possible, notwithstanding every precaution, that some 

 phosphorus may accidentally get on the fingers, it is desirable to 

 have a small quantity of olive oil, as well as an oiled rag close at 

 hand. Phosphorus is very soluble in olive oil, and as the solution 

 is incombustible (spontaneously) an instant application removes the 

 danger. It may seem that this risk has been too much dwelt 

 upon, but as a burn from phosphorus is frequently very severe, it 

 does not appear to the writer to be inopportune to urge the point. 

 The slides may now be put aside for a day or two, when they can be 



