802 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



To illustrate the manner in which Bache advocated the claims 

 of American discoverers and inventors, the speaker read several 

 quotations from the address alluded to, and concluded with 

 the hope that America would preserve on the roll of fame the 

 name of the distingushed citizen whose loss we now deplore. 

 The chairman then presented the following paper : 

 Dr. T. Sterry Hunt, F. R. S., for the past fifteen years associa- 

 ted with Sir William Logan in the geological survey of the Cana- 

 das, has lately delivered twelve lectures before the Lowell Insti- 

 tute of Boston, on chemical and dj-namical geology, which have 

 attracted great attention. Dr. Hunt, although a native of Con- 

 necticut, a graduate of Yale College, and a regular contributor to 

 ■/Sillitnan^s Journal ^ has spent so much time abroad that his Ameri- 

 can orJijin has been lost sicjht of. He has devoted most of his 

 labors to chemical geology, and is now regarded as high authority 

 on all questions connected with that su1)ject. The following 

 seventeen notes have passed under his inspection, and may, there- 

 fore, be accepted as a condensed statement of some of the more 

 prominent and novel points presented in his last course of lectures : 



The Nebular Hypothesis. 

 The revelations of the spectroscope demonstrate that the same 

 chemical elements arc c(jmmbn to the earth, the sun, and the far- 

 therest stars ; and that matter exists throughout space as luminous 

 gas (nebulas), and condensed into luminous suns and non-luminous 

 planets, three conditions, through which, according to the nebular 

 hypothesis, all matter must pass in the process of condensation. 

 There are potent arguments in favor of this hypothesis, which is 

 supported by so many astronomical reasons, and which supposes 

 that not only the bodies of the solar system, but all those which 

 astronomy makes known to us, had a common origin from a vapor- 

 ous mass which once filled immensity. 



Nature of the Sun. 

 The sun is the intensified center of our solar system, and may 

 be rejrarded as a jrreat mass of gaseous matter, so condensed 

 beneath its enormous at-mosphere as to have a specific gravity 

 nearly equal to that of water. This condition is not incompatible 

 with a very elevated temperature, for Cagniard de la Tour's expe- 

 riments afford reason for supposing that at a sufiiciently high 

 temperature and pressure all matter may assume a gaseous form 

 •without any great increase of volume. The temperature required 



