of dark Heat-rays by Gases and Vapours. 

 III. Fermentation — Butyl Alcohol. 



23 













Deflec- 







Name and 



pressure 



of vapour. 



B . 



Reversal-points. 



R r 



tion, in 

 divi- 

 sions 



of the 



Mean. 



J. 















Pi- Pz- 



P3- 



Pr 





scale. 







So 

 II 



Pure dry air. 



447 



448 

 449 



746 

 741 



741 



656 

 653 

 651 



692 

 690 

 691 



665 676-9 229-9 

 670 677-4 2294 

 67lj 677-7 , 228-7 



1 229-3 10000 



op" 

 i— i 

 II 



C 4 H 10 O, 



3 millims. (?) 



445 

 454 

 448 



701 

 715 

 713 



624 

 632 

 633 



656 

 670 

 665 



637 644-2 ' 1992 

 651 657-1 203-1 

 645 652-9 204-9 



1 202-4 



J 



88-27 



Purification by fractional distillation was not possible, 

 because of the small quantity of the substance at our disposal. 



IY. Fermentation — Amyl Alcohol. 



iQ 





6 



214 



142 



175 



153 



1621 



156-1 



1 





°GO 



Pure dry air. 



6 



208 



139 



173 



153 



160-6 



154-6 



L 155-3 



10000 



II 





o 



206 



140 



171 



154 



160-3 



155-3 



J 





Ci 



5 H 12 0, 



tension (?). 



6 



200 



135 



168 



147 



1554 



149-4 



] 





i—i 



6 



204 



140 169 



149 



157-4 



151-4 



I 1512 



97-36 



II 



2 



199 



.138 166 



147 



154-9 



152-9 



J 





Y. Benzol. 



o 



go 



II 



Pure dry air. 



445 

 445 



478 



796 

 799 

 830 



690 746 

 697) 746 

 730 774 



714 

 710 

 740 



725-8 

 725-8 

 755-7 



2808 



280-8 

 277-2 



1 279-6 



100-00 



CO 



r-i 



II 



C 6 H 6 , 



42 millims. 



462 

 440 

 458 



797 



780 

 802 



690 

 670 

 691 



747 

 722 

 739 



713 



687 

 707 



725-9 

 700-8 

 720-1 



263-9 



260-8 

 2621 



1 262-3 



93-81 



Conclusions. 



We have already remarked more than once how great an 

 importance attaches to the investigation of the absorption of 

 radiant heat by gases and vapours in reference to meteoro- 

 logical questions. As far as aqueous vapour is concerned, 

 since the first discussion of this subject by Tyndall until now, 

 there has been no hesitation in ascribing that which has been 

 measured only for a small number of wave-lengths to other 

 wave-lengths, or even to the whole spectrum. Two generali- 

 zations have been made — one to the absorption of the radia- 

 tion of the earth, the other to the absorption of the radiation 

 of the sun by our atmosphere. 



As far as the radiation of the earth is concerned, we have 



