1902.] Expansion of Ice, etc., at Low Temperatures. 245 



naphthalin is about half that of the liquid near its melting-point, 

 viz., 0*000785. If the liquid coefficient be taken at a correspond- 

 ing temperature to that of the liquid carbonic acid when comparing 

 it with the solid, then its value is 0*001213, or the coefficient 

 would be now in the ratio of 4 to 1. The graphite calculated 

 from Fizeau should be 0*0000929, which is greater than my value ; 

 but the samples were different. My two specimens of chloride of 



Table II.— Ice. 



1 



Silver ball. 

 Weight lost in 



(1) oxygen, 



(2) liq. air. 



Density 



of 

 liquid 

 air. 



Weight of ice 

 and copper ball 

 and wire. 



Weight of 

 copper ball 

 and wire. 



Weight 

 of ice 

 in vacuo. 



Density 

 of ice 

 at 



- 188° -7 

 C. 



Gaseous 



air at 

 -188° -7 

 C. 



Liquid 

 air at 

 -188° -7 

 C. 



Air at 

 16° 0. 



Liquid 



air 

 -188° -7 

 C. 



(1) 14-411 



(2) 12-446 



-9820 



47 -080 



33 -430 



38 -075 



33 -933 



9 -0612 

 8-706 



-93032 

 -92646 



(1) 14-409 



(2) 12-042 



-9502 



46-78 



33 -88 



38-128 



84-103 



(1) 14-407 ; . 9942 



(2) 12 -597 ° 9942 



56 -391 



32 -740 



38 -127 



33-94 



18 -167 



0*93318 



Table III. — Solid Carbonic Acid. 



Weight of solid CO.. 



Density of 

 liquid air. 



Weight 

 in vacuo. 



Density at 

 at -188 5 -8 C. 



Gaseous air 

 at -188° -8 C. 



Liquid air 

 at -188° 8 C. 



19 -865 

 22-55 



7 -905 

 9-37 



0-9832 

 0-9502 



19 -919 

 22 -61 



1 -6308 

 1 -6226 



ammonium gave nearly the same value, and the result is in agreement 

 with that found by Playfair and Joule, viz., 0-000191. If a Fizeau 

 coefficient for this salt is calculated, the value is 0*0000761, which in 

 this case is far too small. The coefficient found for oxalic acid is again 

 only a little smaller than that given by Playfair and Joule, viz., 

 0*0002748. As regards the hydrated salts, phosphate of soda, hypo- 

 sulphate of soda, and chloride of calcium, having the respective values 

 0*0001384, 0*0001516, and 0*0006887, as found by Kopp, the low tern- 



