10 



SCIENCE. 



[N. S. Vol. VIII. No. 183. 



With an extension of the time that the 

 metals were held out of the liquid to three 

 seconds, a slight effect of boiling was ap- 

 parent when they were replaced. 



In the determinations of specific heats for 

 low temperatures it required only one sec- 

 ond or less to transfer the metals from the 

 liquid oxygen to the water in the calorim- 

 eter. It, therefore, seems probable that little 

 heat was absorbed by the substances during 

 the time required for their transference from 

 the liquid oxygen to the calorimeter. In 

 the experiments with liquid oxygen trans- 

 ference of the metalic objects from the cold 

 liquid to the water in the calorimeter was 

 accomplished with less difBculty than the 

 transference of the same objects from boil- 

 ing water to the water in the calorimeter, as 

 performed in the preliminary experiments 

 on the specific heat of copper between 23° 

 and 100° C. 



Little or no liquid oxygen was carried 

 over to the calorimeter on the metal pieces, 

 it having boiled oW before they were placed 

 in the water ; therefore a correction similar 

 to that applied in the experiments with boil- 

 ing water was not necessary. 



The value of the specific heat of iron be- 

 tween — 181.4° and 13°, C.,as determined by 

 the foregoing experiments, is .09] 4. 



The lowest value for the range, 15°... 

 100° C, according to recorded results, ap- 

 pears to be about .113 (.1130, 0°...100° C, 

 Tomlinson). 



The value for the specific heat of iron be- 

 tween — 181.4° and 13° is, therefore, approxi- 

 mately 19 per cent, less than the lowest 

 value for the range, 15°--100° C. 



The specific heat of aluminium for the 

 low temperature range was found to be 

 .1833. 



The lowest value for the range 15°---100° 

 C. seems to be about .212 (15°-97° C, 

 Eegnault) . 



The value for the specific heat of this 

 metal between — 181.4° and 15° C. is 13.6 



per cent, less than the lowest value for the 

 range 15°-100° (97°) C. 



The' values for the specific heat for the 

 ranges, 0°-100° C. and 15°--97° C. given, 

 were taken from Physikalish-ehemische Tabel- 

 len, by Landolt and Bornstein, 1894 Ed. 



The variation in the values, as given by 

 diflferent authors, of the specific heat of 

 certain metals for the range 15° •■•100° C. 

 is no doubt partly due to the employment 

 of metals of different degrees of purity. 

 For this reason the specific heat of the 

 pieces of iron and aluminium used in the 

 experiments with liquid oxygen have been 

 determined between 23° and 100° C. in the 

 manner that the specific heat of the copper 

 for the same range was found. 



The determinations were as follows : 



Table 5. 



Mean 



.1162 



The weight of water and other quantities 

 were the same in these experiments as 

 those with copper (23°^^^100°C.). 



The determinations of the specific heat 

 of aluminium between 23°^--100° C. were as 

 follows : 



Table 6. 



Mean .2173 



The accuracy of manipulation in these 

 two sets of determinations was about equal 

 to that of the experiments on copper for the 

 same range of temperature. 



