Prof. Magnus on the Motion of Fluids. 



15 



dered correct. Experience soon enabled us to fix the quantity 

 necessar}' to flow away in order entirely to remove the fluid con- 

 tained in the vessel. 



The strength of the solution was of course changed by the 

 water which entered the vessel ; but this alteration, during the 

 short period necessary for an experiment, was very inconsider- 

 able. Before each fresh experiment, the quantity of salt in the 

 solution contained by the vessel AB was estimated anew. 



33. It was of particular interest to learn whether the salt so- 

 lution penetrated to the centre of the jet. Experiments were 

 first made in which the point was always placed right in the 

 middle of the jet, and at difi'erent distances from the orifice/. 

 In order to eff'ect this, the vessel was emptied by permitting the 

 salt solution to flow away ; and while the vessel was empty, the 

 point was fixed exactly in the centre of the jet. The solution 

 was then poured in again, and the experiments conducted in the 

 manner already described. 



The results so obtained are set down in the following table. 

 The four first columns contain the numbers obtained by direct 

 observation, the fifth column is derived from the third and fourth. 



When the point was brought close up to the orifice through 

 which the water flowed into AB, pure water was obtained which 

 contained not a trace of salt. 



34. The diflerences exhibited by those experiments in which 

 the point stood at the same distance from the orifice, are due to 

 the fact, that the least deviation from the centre necessitates a 

 considerable ditt'crence in the constitution of the mixture. In 

 order to ascertain the extent of this variation, experiments were 



