54 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



c = O.O7II8. Tliis formula of Landolt and Bornstein seems to be 

 taken from PieiTe.^° It gives for the volumes at 20°, 40°, 60°, and 

 80° the values 1.0181, 1.0374, 1.0583, and 1.0814 respectively. We 

 have also the following values by Pierre and Puchot^^; 1.0187, 1.0397, 

 1.0610, and 1.0864. These authors give for the density at 0°, 0.817. 



->. 1.00 



E 

 <j 



I .90 



> 



.80 



mmm 



0123456789 10 11 12 

 Pressure, kgm. / cm.^ x 10^ 

 "Amy! Alcohol 



Figure 12. Amyl Alcohol. Volume at 20°, 40°, G0°, and 80° plotted 

 against pres.sure. The lower curve gives the volume at 20°. 



Zahnder^^ gives for the density- at 0° 0.829, and for the constants of 

 the dilatation formula, a = 0.03919, b = —0.06461, and c = O.O7I75? 

 Here again the discrepancies appear to be greater than they should 

 in measurements of this character. 



For the change of volume between 1 and 500 kgm. there seem to be 

 no other data as a basis of comparison. Amagat used allyl instead of 

 amyl alcohol for some unknown reason. The only course, therefore, 

 was to accept the value given by this present work for the lower 

 pressure interval, namely 0.0451. That this figure is about correct, 

 however, is spoken for by the rather unusually close agreement of the 

 two measurements of the piston displacement at 20°, 0.389 inch and 

 0.379 inch, a disagreement of 2.5%. 



The volume of amyl alcohol as a function of pressure and tempera- 

 ture is shown in Table VIII and in Figure 12. 



30 Pierre, 1. c. (1847). 



31 Pierre and Puchot, Ann. chim. et phys. (4), 22, 306? 



32 Zahnder, 1. c. 



