April 1, 1864.] THE TECHNOLOGIST. 



LABORATORY NOTES. 431 



Proximate Composition of the Coal. 



Water 2-89 



Volatile matter . 7-59 



Fixed carbon (coke) 80-63 



Ash ... . ■ 8-89 



100-00 

 Amount of sulphur in volatile portion . . 4 - 550 

 Amount of sulphur in non-volatile portion . 1-512 



Total amount of sulphur in 100 parts . 6-062 



Percentage of Nitrogen 0'278 



Specific gravity . 1*44 



Coal (third seam) from the detached field north of the Arigua Valley, 

 Seltannaskeagk Colliery, Co. Leitrim. By Wm. J. Wonfor. 



Absolute Heating Power of the Coal. 



13*47 tons of water at 212 deg. F. converted into steam by 1 lb. of 

 the coal. 



1246"0 lbs. of water at 212 deg. F. converted into steam by 1 cubic 

 foot of the coal. 



Proximate Composition of the Coal. 



Water 1-08 



Volatile matter 20-16 



Fixed carbon (coke) 74-66 



Ash .... ... 4-10 



10000 



Amount of sulphur in volatile portion . . 0-596 



Amount of sulphur in non-volatile portion . . 0-531 



Total amount of sulphur in 100 parts . 1-127 



Percentage of nitrogen 136 



Specific gravity 1*48 



(To be continued.) 



Amount of Tannin in some Astringent Substances. — By M. 

 Hanratty and T. H. Fletcher, Students in the Laboratory of the 

 Museum of Irish Industry, Dublin. 



The following estimations of Tannin were made in a manner similar 

 to that pursued by our late fellow students, Messrs. Mulligam and 

 Dowling : — 



Per Centage of 

 Tannin. 

 Rizophora Mangle (Rizophoracece), Tropics . . 827 

 Crabwood, Xilocarpus Carapa, (Meliaceai,) Brazil 3"65 

 Bark of the Greenheart, Nectandra Rodiei, 



(Lauraceos,) Demerara 10-17 



Birch Bark (Betula) 4"33 



Bark of the Blakea triplinervis (Melastomacece) 



Guiana 1-32 



Gaub fruit of Diospyros embryopteris . . 17'82 



Wild Pomegranate Buds (Balaustines) . . 45 - 58 



Sodom Apple Galls . ) . . 47 "20 



