TRANSACTIONS OF THE SECTIONS. 



69 



On a Method of determining with accuracy the Ratio of the Rotating Power of 

 Cane-svgar and Inverted Sugar. By the Eev. Professor Jellett, M.A.f 



On the Action of Hydroclihric Acid on Morphia Codeia. 

 By Dr. A. Matthiessen, F.R.S., F.C.S., and C. R. Weight. 



Are Flint Instmments of the first Stone Age found in the Drift ? 

 By W. D. Mitchell. 



On the Economic Distillation of Gas from Cannel-Coal. 

 By Dr. Stevenson Macadam, F.R.S.E., F.G.S. 



The experimental observations which form the basis of the present communica- 

 tion were undertaken for the purpose of determining the quantity and quality ot 

 gas obtained from certain mixtures of cannel-coals as contrasted with the gas dis- 

 tilled from the coals taken separately. The coals selected for examination by de- 

 structive distillation were sixteen in number, and they comprehended examples ot 

 the larger coal-fields in Scotland. The experiments were conducted in a small gas- 

 work attached to the laboratory of the author, and connected with fully equipped 

 photometric apparatus. The quantity of coal experimented upon at a time was six 

 pounds, and the volume of gas vielded therefrom amounted to about thirty cubic 

 feet. Every possible care was taken to keep the retorts at a imiform temperature 

 during the course of the trials, and the testing of the same coal on several occa- 

 sions showed that such was practicallv done. ,• i? 



The coals employed in the experiments, and the quantity and quahty ot gas ob- 

 tained therefrom, may be observed from the following Table : — 



Yield and Quality of Gas fi-om Cannel-Coals taken separately. 



No. 



Name of coal. 



Gas, 

 per ton of coal 

 in cubic feet. 



Illuminating- 



pcwer of the 



gas (5 cubic 



feet per hour) 



in candles. 



*1. 

 2. 

 3. 



#4. 

 5- 



«6. 

 7. 



#8. 



#9. 

 *10. 



11. 



12. 



13. 



14. 

 #15. 

 #16. 



Bredisbolm or Provanball . 



Shields 



Bank, main seam 



Clewch 



Wilsontown 



Muirkii-k 



Eigside 



Clinipy 



Bank. 5 ft. seam 



Pollok 



Huntersliill 



S. Boig or Lower Lanemark 



Upper Lanemark 



Eaplocb 



Haywood .. 



Einneil 



9,434 

 10,703 

 11,524 

 11,452 

 10,666 

 10,552 

 11,490 

 10,928 



9,768 

 11, .525 

 10,030 



9,881 

 10,479 

 10,966 

 11,153 

 11,789 



26-81 

 21-22 

 19-82 

 29-39 

 25-31 

 37-16 

 32-31 

 38-68 

 27-07 

 30-26 

 22-66 

 24-39 

 24-56 

 17-05 

 30-97 

 30-60 



Considering the original cost of the coals, the eight samples marked with an 



t ride ^.23. 



