CONCLUSION. 67 



amalgam approaches the theoretical value required by the gas law more and 

 more closely as dilution proceeds. The further fact that one of these series 

 of results approaches the limiting value from below and the other from 

 above increases the probability that the gas law holds perfectly in solutions 

 of infinitesimal concentration. From the lower side we have approached the 

 ideal value within 0.3 per cent, from the upper side within 0.2 per cent, and 

 have seen that further dilution would undoubtedly yield yet closer results. 

 The osmotic pressure of zinc or cadmium in the most dilute amalgams 

 investigated was about one atmosphere; it is interesting to note that the 

 irregularities in p v existing here appear scarcely greater than those of 

 oxygen and hydrogen gases, whose molal volumes are 22.39 and 22.44 liters, 

 respectively, under normal conditions. This outcome seems to be incon- 

 sistent with the idea that the hypothetical bulk of the molecules of solvent 

 affects the osmotic pressure. 



Without doubt the present research thus gives the most rigid experimental 

 proof of the exactness of the gas law in dilute mercurial solutions ever 

 obtained. Whether so close an approach has ever been noted in other 

 solvents is doubtful. 



In concluding this somewhat lengthy and troublesome investigation, it is 

 a pleasure to acknowledge the important pecuniary aid generously granted 

 by the Carnegie Institution of Washington. This support materially facili- 

 tated the work. 



