Harrington — Modification of Victor Meyer's Apparatus. 225 



Art. XXY. — A Modification of Victor Meyer's Apparatus 

 for the Determination of Vapor- Densities ; by B.J. 

 Harrington. 



The ingenious apparatus devised by the late Professor 

 Yictor Meyer for the determination of vapor-densities has 

 been in use for many years aud has proved of great value for 

 the purpose for which it was intended. It, however, lias 

 certain imperfections, being awkward on account of its height 

 and very liable to be broken, especially in the hands of inex- 

 perienced workers. Two modified forms of the apparatus 

 have been devised by the writer and have proved so useful in 

 our own laboratories that it has been deemed worth while to 

 publish a description of them. In both cases an attempt was 

 made to simplify the apparatus and make it more convenient 

 and rapid to work with. 



The first form tried is that shown as fig. I in the accompany- 

 ing illustration. It will be observed that the receptacle del is 

 horizontal instead of vertical and that the long stem of Meyer's 

 aj>paratus is bent upon itself a number of times ; the apparatus 

 accordingly occupying but little space. Instead of the long 

 outer tube or jacket ordinarily employed, a box made of tinned 

 iron or copper is used. 



In making an actual determination the space around the 

 glass at m and k (fig. II) is packed with a little asbestus, and 

 it has been found advantageous to lay a piece of asbestus card 

 on the cover of the box. 



The weighed material in the ordinary stoppered tube or 

 bulb is dropped in at e (fig. I) and as it has not far to fall 

 there is no need of the usual cushion of asbestus or sand. As 

 soon as one operation is completed the vapour is quickly swept 

 out of the apparatus by connecting the tube ah (fig. I) with 

 the vacuum-pump, the water in the box ff (fig. II) being kept 

 continuously boiling. In this way one operation quickly 

 succeeds another, and it has been found that students can make 

 two or three determinations in the time required for one with 

 the ordinary apparatus. 



The second form experimented with is shown at III. In 

 this the receptacle dd of I is placed vertically, as it was 

 thought that the vapor would be less likely to be carried into 

 the delivery tube than if the horizontal position were adopted. 

 The tube e is somewhat longer than in the first form (I) but 

 the curve at the bottom checks the velocity of the little tube 

 containing the liquid and no asbestus is required at the bottom 



