of Expansion of Gas-Solutions, 115 



To obtain with accuracy the temperature of a large bulb, 

 by means of a thermometer in the bath outside, two precau- 

 tions must be taken. The bath must be continually stirred, 

 and after each change of temperature it must be kept at a 

 constant temperature until the entire contents of the bulb shall 

 have assumed that temperature. We found, by a series of 

 preliminary trials, the time necessary to this end to be thirty 

 minutes after a 1° to 2° change of temperature, and thirty-five 

 minutes after a 5° change. 



In our determinations five different solutions of ammonia 

 gas were used. The specific gravity of each solution as ob- 

 tained at the time of filling the dilatometer with the same, 

 together with the strength of the solutions, appears in Table I. 



Table I. 



No. of solution. 



Specific gravity 

 at 14° 0. 



Percentage of NH 3 

 in solution. 



1. 

 2. 

 3. 

 4. 

 5. 



•9009 

 •9373 

 •9676 

 •9766 

 •9913 



2900 per cent. 

 16-19 



7-96 „ 



5-61 



212 



Table II. gives the volumes of these different solutions for 

 various temperatures, compared with the volume of each at 

 4° C. taken as unity, and calculated directly from our obser- 

 vations. The dilatometer a was used with solutions 1 and 2, 

 and dilatometer b with solutions 3, 4, and 5. 



Table II. — Volume Table. Observed Values. 



Percentage of NH 3 in solu- 

 tion = 29*00 per cent. 



Temperatures. 



Eaudin 



Air-ther- 



7313. 



mometer. 



o 



o 



15 



1500 



13 



1301 



11 



11-06 



9 



915 



7 



7-28 



5 



5-33 



3 



3-27 



1 



1-16 



-1 



-080 



-3 



-2-51 



-5 



-4-38 



-7 



-6-40 



Observed volumes 



compared with the 



volume at 4° as 



unity. 



1-007214 

 1-005835 

 1-004547 

 1-003303 

 1-002064 

 1-000862 

 0-999618 

 0-998350 

 0-997109 

 0-996020 

 0-994838 

 0-993585 



Percentage of NH 3 in solu- 

 tion = 16*19 per cent. 



Temperatures. 



Golaz. 



(Air-ther- 

 mometer, 



22 



17 



12 



7 



2 



- 3 



- 8 

 -13 

 -17 



21-80 



16-80 



11-80 



6-80 



1-80 



■ 3-20 



■ 8-20 

 ■13-20 



17-20 



Observed volumes 



compared with the 



volume at 4° as 



unity. 



1-007129 

 1-004930 

 1-002874 

 1-001013 

 0999110 

 0-997514 

 0-996095 

 0-994890 

 0-994139 



12 



