348 PROCEEDINGS OF THE CALIFORNIA 



Analysis of Mt. Diablo (California) Coal. 



BY W. P. BLAKE. 



A sample of Mt. Diablo coal, from the Pittsburg mine, was analyzed by me 

 in January last, with the following results : 



Water 3.28 



Bituminous substances 47.05 



Fixed carbon 44.90 



Ash 4.71 



The sample was very pure, and apparently free from sulphur. Color black. 

 Fracture sub-conchoidal, giving brilliant shining surfaces. It is very brittle, 

 and is easily reduced to powder in a mortar. Streak, dark brown. 



This coal does not fuse so as to cake and make a compact mass of coke. It 

 is not therefore an economical coal for gas production. It gives a long flame 

 in burning ; parts with its gas rapidly and breaks up into small fragments, thus 

 necessitating the use of grate-bars with narrow openings. The above analysis 

 differs from those hitherto published, chiefly in the amount of water and gas. 

 Former analyses give from thirteen to fourteen per cent, of water. 



Mr. Hanks presented an analysis of the rock-salt collected 

 by Major Lyon on the Muddy River, as mentioned in the proceed- 

 ings of the last meeting. 



On Saturday, April 6th, the Academy made a field excursion to 

 Angel Island, about fifteen members participating in the meeting. 

 Facilities were afforded for the excursion by Major James T. Hoyt 

 and General John A. King ; and to these gentlemen the thanks of 

 the Academy were ordered to be returned by the Secretary. 



Regular Meeting, April 15th, 1867. 



Vice President Ransom in the Chair. 



Thirtv-three members present. 



The collections made during the field meeting on Angel Island 

 were exhibited and commented on. 



