42 Reports & Proceedings — Edinburgh Geological Society. 



The texture of the aplite is microgranitic. The principal 

 minerals are albite, orthoclase, microperthite, quartz, lepidolite, 

 green tourmaline, and topaz. Blue apatite is almost entitled to 

 be classed with these. Fluorspar, montmorillonite, and axinite are 

 accessories. Although, in conformity with other observers, the 

 author has described this rock as an aplite, he uses the term with 

 reservations. The rock is neither more acid than the normal 

 granite, nor does it approach freedom from mica, and lie submits 

 that the true description, even if cumbrous, would be lepidolite- 

 soda-granite. The whole of the mica is apparently lepidolite, and of 

 8"70 per cent, the total of the alkalies, roughly five-eighths are soda 

 and three-eighths potash. 



Some veins of true granite occur, always of fine grain : in these 

 andalusite is locally developed. It is noted that topaz and andalusite 

 have never yet been found side by side in any Dartmoor granite or 

 granite vein, but topaz may occur in granite which is in contact 

 with slate in which andalusite is present. In one and the same rock 

 the minerals appear to be mutually exclusive, or, in other words, 

 when the conditions are such that topaz may form andalusite is not 

 to be expected. 



II. — Edinburgh Geological Society. 

 October 16, 1 1918. — Professor Jehu, President, in the Chair. 



"Peat and its Utilisation." An Address by H. M. Cadell, B.Sc, 

 E.R.S.E., Vice-President. 



At times such as these, when the Great War had emphasised the 

 need of conserving all natural and scientific resources, the peat question 

 deserved its full share of attention. The high price and scarcity of 

 coal made the prospect of success in the working of peat greater than 

 it had ever been. During recent years peat had been found valuable 

 for producing many other things besides ordinary fuel. By wet or 

 dry distillation, peat products included alcohol suitable for internal 

 combustion engines, ammonia for agricultural fertilisers, acetic acid 

 and acetone for explosives, paraffin for making wax, creosote for 

 preserving timber, tar for coating roads, oil and spirit for burning 

 and power production, as well as gas and coke for heating and 

 smelting. Besides these more or less complex products, the fibrous 

 red peat of the surface of bogs was of great value for moss litter for 

 bedding horses and cattle, and peat dust was useful for packing 

 fragile objects such as eggs and fruit. Cardboard and brown paper, 

 suitable for packing, had been successfully made in America from peat 

 as a substitute for wood pulp, and as timber was now becoming scarce 

 much saving might be made by this use of peat, which was one of 

 the most abundant, but least developed, of our natural resources. 



Immense areas of undeveloped peat moss occurred both in Europe 

 and America, the utilisation of which would not only provide good 

 fuel and other valuable things, but would afford useful employment 

 to a large population in many otherwise poor rural districts. In 

 Europe the peat mosses covered over 200,000 square miles, and in 

 1 Received November 16, 1918. 



