120 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



ter consisted of about seventy-five per cent, of a clayey sub- 

 stance, colored yellow by oxide of iron, eleven per cent, of 

 carbonate of lime, and about fourteen per cent, of organic 

 matter. In this the microscope revealed numerous vegetable 

 fragments, such as hairs of plants, membrane, scales, seeds, 

 etc., with various diatoms and living infusoria, while the wa- 

 ter contained carbonate of lime, carbonate of magnesia, car- 

 bonate of iron, sulphate of lime, chloride of potassium, sul- 

 phate of soda, etc. 18 C.June 12,1872,377. 



ORIGIN OF COAL. 



According to Professor Wiirtz, the formation of coal de- 

 pends entirely upon the action of the iron which was dissolved 

 in the waters of the coal period. The combinations of iron 

 with which coal is always accompanied are pyrites, iron spar, 

 and hydrated oxide. These were doubtless derived from the 

 strata interjected between the coal-beds. In this case the 

 oxygenated water appeared to act upon the metallic sulphur- 

 ets w r hich were contained in the crystalline slates, from the 

 destruction of which these coal strata were derived. Coal, 

 consequently, is the normal result of the eremacausis of or- 

 ganic substances in waters which contain sulphate of iron 

 and free carbonic acid. An immense pressure upon the mass, 

 while in a plastic condition, was also, without doubt, an addi- 

 tional element of importance. 9 (7, Nov., 1871, 86. 



DISCOVERY OF COAL IN CHILE. 



Late Chilian papers announce the discovery of important 

 mines of coal in that country, especially along the Gulf of 

 Aranco, near the mouth of the Carampangue River. Accord- 

 ing to an official report, one of these veins is five feet thick, 

 and is estimated to contain four million tons of coal. Pan- 

 ama Star and Herald, April 19, 1872, 3. 



FRESHWATER LAKES. 



It is generally supposed that lakes and other bodies of 

 water which receive the final drainage of streams, and are 

 themselves without an outlet, are more or less salt an in- 

 stance of this being seen in the Great Salt Lake of North 

 America, and in other bodies of water. It is said, however, 

 that the waters of Lake Peten, in Yucatan, are fresh, though 



