THE COMPRESSIBILITIES OF THE MORE IMPORTANT SOLID 

 ELEMENTS, AND THEIR PERIODIC RELATIONS. 



INTRODUCTION. 



In continuing the research upon compressibilities, it was desired to 

 obtain a series of results from many of the more important elements, in 

 order to discover their relation to one another, and to obtain as much light 

 as possible upon the internal structure of solids in general. Accordingly, 

 magnesium, calcium, zinc, cadmium, copper, silver, gold, palladium, plati- 

 num, tin, lead, thallium, aluminum, iron, manganese, nickel, chromium, 

 molybdenum, arsenic, antimony, and bismuth were all studied, and the 

 interesting results obtained from this study are detailed below. 



The method of investigation was essentially similar to that already 

 detailed in the preceding papers upon the compressibilities of the alkaline 

 metals and the non-metals. Because of the less violent chemical nature of 

 most of the heavier elements, the new problem was simpler than in the 

 case of the alkaline metals, but because, on the other hand, their com- 

 pressibilities for the most part are extremely small (often less than 1 per 

 cent of the compressibility of water), great accuracy was needed in the 

 conduct of the experiments. 



The method of procedure was in this case, as before, the following. In 

 the first place, the amount of mercury needed in a suitably, arranged glass 

 jacket for precisely attaining electrical contact with a very finely pointed 

 platinum wire was determined at various pressures. The metal under 

 examination was then immersed in the mercury and a similar series of 

 experiments was once more conducted. Because nearly all of these metals 

 had a compressibility less than that of mercury, less additional mercury 

 would have been needed for a given pressure when the metal was present 

 than when it was not present, except for the fact that in order to protect 

 the metal, some other liquid besides mercury was also put into the jacket 

 and compressed at the same time. As has been shown in the preceding 

 papers, the correction for this other liquid is easily and exactly applied if 

 its compressibility is known. The following pages describe as briefly as 

 possible the essential details of the various processes. 



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