16 



Day, etc. — Determination of Mineral 



Table II. 



Example of Determinations of Specific Volume of Quartz. 



Date 21 January, 1911 



Weight of specimen 34 - 12 g. 



Weight of cage, etc. 94' 17 g. 



Volume graphite crucible at 0° 8 "21 cc. 



Metal used Tin. 















Kilo- 



Temp. 



Total wt. 



Dens, tin 



Total 

 volume 



Volume 

 graphite. 



Volume 

 quartz 



volume 

 quartz 

 1000 v. 



20 











12-877 



3775 



450 



146" 



6 



6 



844 



21 



42 



8 



23 



13-19 



386-6 



514 



146 



7 



6 



806 



21 



55 



8 



23 



1332 



3905 



550 



146 



5 



6 



785 



21 



59 



8 



23 



13-36 



391-6 



561 



146 



5 



6 



778 



21 



61 



8 



23 



13-38 



3922 



585 



147 



3 



5 



764 



21 



78 



8 



23 



13-55 



3972 



600 



147 



1 



6 



755 



21 



78 



8 



23 



13-55 



397-2 



650 



146 



4 



6 



725 



21 



77 



8 



24 



13-53 



3966 



701 



145 



6 



6 



694 



21 



75 



8 



24 



1351 



396-0 



755 



145 







6 



663 



21 



76 



8 



24 



13-52 



3963 



800 



144 



3 



6 



637 



21 



74 



8 



25 



13-49 



395-4 



850 



143 



7 



6 



607 



21 



75 



8 



25 



13-50 



395-7 



900 



143 







6 



578 



21 



74 



8 



25 



13-49 



395-4 



950 



143 



1* 



6 



548 



(21 



85) 



8 



26 



(13-59) 



(398-4) 



1091 



143 



8f 



6 



464 



(22 



3) 



8 



27 



(14-0) 



(41 0-) 



1167 



142 



3t 



6 



419 



(22 



2) 



8 



28 



(13-9) 



(407-) 



1175 



141 



3f 



6 



414 



(22 



0) 



8 



28 



(13-7) 



(403 •) 



1204 



140 



6f 



6 



397 



(21 



98) 



8 



28 



(13-7) 



(402 •) 



1250 



138 



8t 



6 



370 



21 



79 



8 



29 



13-50 



395-7 



1300 



138 



3 



6 



340 



21 



81 



8 



29 



13-52 



3963 



1350 



138 







6 



310 



21 



87 



8 



30 



13-57 



397-8 



1392 



138 



2 



6 



285 



21 



99 



8 



31 



13-68 



401-0 



1400 



138 



3 



6 



280 



22 



02 



8 



31 



13-71 



401-9 



1450 



139 



4 



6 



250 



22 



30 



8 



31 



13-99 



410-1 



1500 



139 



9 



6 



221 



22 



49 



8 



32 



14-17 



415-4 



1550 



142 







6 



192 



22 



93 



8 



33 



14-60 



428-0 



1594 



144 



2 



6 



166 



23 



39 



8 



34 



15 05 



441-2 



1602 



146-4 



6-161 



23-76 



8-34 



15-42 



4520 



* Gas evolution beginning, f Gas escaping rapidly. % Gas evolution ceased. 



The volumes of the float-crucible and of the quartz at 20° 

 were determined by replacing the molten tin by mercury. The 

 volume of the sample was also checked by weighing under 

 water in the usual manner. 



All of the experimental data on quartz are plotted in fig. 6, 

 and the six series of measurements are listed in Table III. As 

 will be seen from the curve, the volume increases more and 

 more rapidly as the inversion temperature (575°) is approached. 

 Beyond that temperature the volume seems to decrease slightly. 

 The escape of gases beyond 950° interrupts the measurements, 

 and the points shown in the figure represent merely chance 



