152 Royal Society : — 



Five series were made with mercury ; and its expansions, deduced 

 from the water-expansions given in Table L, were 



Series I V,=V (1 + 0-00018150, 



Series II V*=V (1 +0-0001813*), 



Series III V*-=V (1+0*00018080, 



Series IV V*=V (1+0-00018080, 



Series V V,=V (1+0-00018160, 



Mean .... V*=*V (1 + 0-00018120, 



a value closely agreeing with Regnault's, namely 



V,=V (l+0-0001815O. 



Calculating from the five series the coefficients of expansion of mer- 

 cury, using Kopp's water-expansion (taking the volume at 4°=1), 

 we find as mean 



V,=V (1 + 0-0001 780- 



In the following Table I give the values obtained by different ob- 

 servers for the volumes occupied by water at different temperatures, 

 the volume at 4° being taken equal to 1 . 



Table II. 



T. 



Kopp *. 



Despretzt. 



Pierre $. 



Hagen §. 



Matthiessen. 



o 



4 



I'OOOOOO 



I 'OOOOOO 



I 'OOOOOO 



i*oooooo 



I 'OOOOOO 



IO 



I -000247 



1*000268 



1*000271 



1*000269 



1*000271 



15 



1 -00081 8 



1*000875 



1*000850 



1*000849 



1*000892 



20 



1*001690 



1*001790 



1*001717 



1-001721 



1-001814 



3° 



1*004187 



1*004330 



1 -0041 95 



1-004250 



1-004345 



40 



1*007654 



1*007730 



1-007636 



1-007711 



1*007730 



50 



1*011890 



1*012050 



1-011939 



1-011994 



1*011969 



60 



1-016715 



1-016980 



1-017243 



1*017001 



1*016964 



70 



1*022371 



1*022550 



1*023064 



1-022675 



1*022648 



80 



1*028707 



1-028850 



1*029486 



1-028932 



1-028953 



90 



1*035524 



1*035660 



1*036421 



1-035715 



1-035813 



100 



1*043114 



1*043150 



1*043777 



1*042969 



1-043159 



Kopp, Despretz, and Pierre used the same method for their de- 

 terminations — that of determining the expansion of water in glass ves- 

 sels (dilatometers). Hagen employed the weighing process, but at 

 high temperatures employed no special precautions to prevent the 

 steam condensing on his fine wire ; hence his values at 90° and 100° 

 fall below mine. 



* Pogg. Ann. xcii. 42. t Ann. de Chim. et de Phys. lxx. (l re ser.) 1. 



J Ann. de Chim. etde Phys.xiii. (3 me ser.) 325. Calculated by Frankenheim, 

 Pogg. Ann. xcvi. 451. 



§ Abhandlungen d. k. Acad, der Wissensch. zu Berlin, 1865. 



