GEOLOGY. 291 



come by perseverance and patience, and in this also we Lave not been 

 disappointed, for I may now venture to assert that our ultimate suc- 

 cess, with respect to a number of substances, is beyond doubt, With- 

 out the engineering resources, however, at Mr. Fairbairn's command, 

 success would have been hopeless. 



At present our experiments have been restricted to a few substan- 

 ces, and those of easy fusibility ; but I believe our apparatus to be now 

 so complete for a considerable range of temperature, that we shall have 

 no difficulty in obtaining further results. Those already obtained indi- 

 cate an increase in the temperature of fusion proportional to the press- 

 ure to which the fused mass is subjected. In employing a pressure of 

 about 13,000 Ibs. to the square inch on bleached wax, the increase in 

 the temperature of fusion was not less than 30 Fahr., about one- 

 fifth of the whole temperature at which it melts undeivthe pressure of 

 the atmosphere. We have not yet ascertained the degree in which 

 the conductive power of any substance may be increased when solidi- 

 fied under great pressure. This point we hope to investigate with 

 due care ; and also to determine the effects on substances thus solidi- 

 fied, with respect to their density, strength, crystalline forms, and gen- 

 eral molecular structure. We thus hope to obtain results of general 

 interest and value, as well as those which may bear more directly on 

 the questions which first suggested the experiments. 



OX THE TERTIARY FORMATIONS OF ST. DOMINGO. 



The following is an abstract of a paper recently read before the 

 London Geological Societv, bv Col. Heneken and Mr. Lonsdalc. In 



I i V * 



the north-east part of the island of St. Domingo, the river Yaqui flows 

 in a west north-west direction, through a plain four or five miles wide, 

 flanked on its northern boundary by the Cordillera of Monte Christi, 

 and on its southern by the Cibao mountains. The Monte Christi 

 range rises to the height of 3500 feet, and consists principally of com- 

 pact limestone, covered with shales and sandstone, and believed to be 

 of secondary age. The northern fiank of the Cibao mountains on the 

 south also consists of beds, presumed to be of secondary age ; but their 

 more central ridge, which rises to the height of 6000 feet, consists of 

 granite, porphyry, chlorite slate, and other crystalline rocks. Between 

 these two mountain chains, and following the course of the river Ya- 

 qui, the tertiary beds occur, forming a line of low hills, which extend 

 from Santiago to Manchineel Bay, a distance of nearly 70 miles. The 

 lowest beds consist of green shales, in many places full of fossils. Ten 

 species of corals, one hundred and sixty-three of mollusca, and the 

 teeth of four species of fish have been procured from these beds. The 

 corals are all believed to be extinct species ; some of them belong to 

 genera only known in the fossil state ; and one of them cannot be 

 referred to any known genus. Of the mollusca, sixteen species are 

 believed to be identical with recent species, most of them now living 

 in the adjacent seas. Three oi' them a Malea, a Triton, and a Ve- 

 nus cannot be distinguished from shells living in the Pacific. Only 



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