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fastened. The other side of (he channel in tlic siiulter piece At is 

 connected through a cone and nut /v ^) with a steel capillary tul)e 

 0, which leads to the before mentioned cock H. The construction 

 of this cock appears from (ig. 8. The tube always remains in 

 communication witli the righthand side opening, which opens again 

 into a steel tube Q' , which leads further to the mercury vessel R. 

 By opening or closing the cock H we can, however, bring in 

 connection with, resp. shut off from the glass jar G in the iron 

 vessel D. The mercury vessel R is by means of a steel tube S.^ in 

 communication with a high pressure cock T, which can etfect or 

 prevent the communication with the steel tube S^. And finally this 

 tube /Sj again leads to the before mentioned high pressure three- 

 way cock P. The construction of this cock appears from fig. 9. 

 The stopper t only serves to shut off an opening, through which 

 at the end of an experiment when one wants to lead back the gas 

 into the jar G, oil can escape. It is seen that S^ is always in 

 communication with a third tube S^, but that a communication can 

 be made or broken off of S^ and S, with the tube ƒ and so with 

 the second pressure stage by the opening or the closure of P. *S, 

 terminates in a T-piece U, which on one side is in communication 

 through the tube S^ with the upper side of the observation vessel 

 L in entirely the same way as the tube with the bottom side, 



Fig, 9. Cock P. 

 on the other side through S, with the hydrostatic press, which 

 causes the pressure. 



1) Gf. the description of these conueclions lower down. 



