464 



the end of Comiii. 70. No great value can be ascribed to the extra- 

 polation by means of this formula, which is valid for pressures 

 above 100 atmospheres from 100 down to 60 atmospheres, but in 

 the neighbourhood of 90 atmospheres the formula probably represents 

 correctly to one or two parts in a thousand what would follow 

 from Amagat's observations. 



Leaving out of account the observation at 90 atmosplieres on the 

 ground of a priori doubt as to its accuracy, although from the 

 next communication it will appear, that it is really affected by a 

 much smaller error than the others and that it would lead to a 

 different conclusion, our results would seem to show, that an extra- 

 polation above 60 atmospheres with Schalkwijk's formula calculated 

 for 4 to 60 atmospheres, although not giving the same accuracy in 

 that region, is still sufficiently accurate to support the suggestion, 

 that Amagat's value at 100 atmospheres is too high. The error 

 would however be less than y^, the amount deduced from Schalk- 

 wijk's formula. 



