522 



PROFESSOR DITTMAR AND MR C. A. FAWSITT ON 



A 



50°, 60°, 65°. To check the results we also determined the capacities 

 for mercury at a similar series of temperatures. From the sum total 

 of our experiments we calculated a formula C = C 4- kt for the capacity 

 at f in grammes of water of the density corresponding to 4°C. (i.e., the 

 capacity in c.cs.), adopting such values for C and k as fell in best 

 with our best determinations. 



In all these determinations, as also in those of the capacities for 

 alcohol, the temperature 0° was established by means of a bath of 

 melting ice, higher temperatures by means of a water-bath. The 

 alcohol operated upon was protected against atmospheric moisture 

 by means of a dried well-fitting cork inserted in the funnel-shaped 

 tap of the bottle. The exact tare of the bottle was taken without 

 the cork ; but in the weighing the cork (compensated for by a piece 

 of metal placed in the other pan) was left on until the still remaining 

 difference of weight could be determined (after the removal of the 

 cork and of its tare) by three consecutive readings of the oscillating 

 needle. The results are given in the table on next page : — t gives the 





Vapour Tension of Methyl- Alcohol in . 



Millimetres of Met 



•cury of 0° 



C. 



Temp. 



Tension. 



Diff. 



Temp. 



Tension. 



Diff. 



Temp. 



Tension. 



Diff. 



0° 



29-7 





25° 



122-7 



+ 6-2 



50° 



409-4 



+ 17-7 



1° 



31-6 



+ 1-9 



26° 



129-3 



6-6 



51° 



427-7 



18-3 



2° 



33-6 



2-0 



27° 



136-2 



6-9 



52° 



446-6 



18-9 



3° 



35-6 



2-0 



28° 



143-4 



7-2 



53° 



466-3 



19-7 



4° 



37-8 



2-2 



29° 



151-0 



7-6 



54° 



486-6 



20-3 



5° 



40-2 



2-4 



30° 



158-9 



7-9 



55° 



507-7 



21-1 



6° 



42-6 



2-4 



31° 



1671 



8-2 



56° 



529-5 



21-8 



7° 



45-2 



2-6 



32° 



175-7 



8-6 



57° 



552-0 



22-5 



8° 



47-9 



2-7 



33° 



184-7 



9-0 



58° 



575-3 



23-3 



9° 



50-8 



2-9 



34° 



1941 



9-4 



59° 



599-4 



241 



10° 



53-8 



3-0 



35° 



203-9 



9-8 



60° 



624-3 



24-9 



11° 



57-0 



3-2 



36° 



2141 



10-2 



61° 



650-0 



25-7 



12° 



60-3 



3-3 



37° 



2247 



10-6 



62° 



076-5 



26-5 



13° 



63-8 



3-5 



38° 



235-8 



11-1 



63° 



703-8 



27-3 



14° 



67-5 



3-7 



39° 



2474 



11-6 



64° 



732-0 



28-2 



15° 



71-4 



3-9 



40° 



259-4 



12-0 



65° 



761-1 



29-1 



16° 



75-5 



4-1 



41° 



271-9 



12-5 



66° 



791-1 



30-0 



17° 



79-8 



4-3 



42° 



285-0 



13-1 



67° 



822-0 



30-9 



18° 



84-3 



4-5 



4-7 



43° 

 44° 



298-5 

 312-6 



1 3-5 









19° 



89-0 



14-1 



64°-96 



7600 





20° 



94-0 



5-0 



45° 



3273 



14-7 









21° 



992 



5-2 



46° 



342-5 



15-2 









22° 



104-7 



5-5 



47° 



358-3 



15-8 









23° 



110-4 



5-7 



48° 



374-7 



164 









24° 



116-5 



61 



49° 



391-7 



17-0 









