AMERICAN INSTITUTE. 427 



Mr. Stetson. — As an engineer, I prefer to make myself tliorouglily ac- 

 quainted with all that has been done before attempting further plana. The 

 extraction of the valuable matters contained in our vast coal mines, in such 

 economical way as to supply light only for millions of people, has a vast 

 value. 



John Johnson. — A difficulty in causing a uniform heat in masses of coal 

 for distillation, must be overcome before we can be successful. That heat 

 must be so moderate as not to destroy the products wanted, for it is so 

 readily gassified that we readily lose our results. 



Mr. Sceley has had some practical acquaintance with this matter. Bi- 

 tuminous coal yields the desired products to some extent. Asphaltura may 

 be dissolved in alcohol, giving opportunity to examine its constituents more 

 perfectly. By heat they readily become gas instead of oil. Tubes of con- 

 siderable length will be necessary for condensation of the coal products. 

 T believe the gas tar comes over first, then the valuable constituents, beur- 

 zole, paraffine, kerosine and naphtaline. I have experimented the last five 

 years on this subject. To make suitable extraction, we must contrive to 

 heat the mass of coal equally at the center and outside. Bars of iroA 

 heated ontside of the viass, may conduct sufficient heat to its center. 



Mr. Meigs. — In all cases should not the mass be well reduced in its 

 pieces — pulverized, or nearly so ? 



Mr. Seeley. — No doubt. And all the products must be drawn off to- 

 gether, and subsequently separated. 



Mr. Veeder has dealt in oils and devoted attention to coal oil, &c. "We 

 want the views of men of science and practice too, qn this occasion. We 

 must get at the fundamental principles — the philosophy of the thing — be- 

 fore we can succeed. Gas is the usual product, and that at no very high 

 temperature. Each particle of oil (as I understand it) is composed o? hy- 

 drogen and carbon, at a certain temperature. The New Brunswick Cannel 

 and the Bituminous coal, give out gas and oil at about TOO'^ to 900'^ Fahr. 

 Benzole (in the distillation) comes off Tir*^, naphtaline 5 eco?i£?, oil third, 

 paraffi.ne last. AVhen the heat continues twenty-four hours, we get the 

 largest quantity of oil. Sulphur is a troublesome constituent of the coal, 

 and must be got rid of. It goes along with the other products through 

 all the processes. There is an establishment here using in one mass of 

 about twenty-five tons of coal, and arc about using sixty to?is. I advised 

 the use of fifty tons in one mass two years ago. I advise the establish- 

 ment of the works at the mouths of the coal mines. We can cheaply carry 

 the products to market, but not the coals to our works. Coal oil, to be a 

 national blessing, must be cheap. 



Mr. Dwight, of New Haven, asked the constituents of benzoic. 



Mr. Reid illustrated on the black-board, and explained the construction 

 of works with the spiral tube or worm, similar to the distillery process, for 

 receiving and condensing the coal products. The wood fired on top of the 

 coal, air sucked downward through the coal, actual combustion prevented 

 as in the pyroligneous retort. 



