1872.] On some Properties of Anhydrous Liquefied Ammonia. 441 



temperature which Hopkins has shown cannot be referred to a cooling 

 nucleus and to differences of conductivity alone. He further shows that 

 this view of the origin of volcanic heat is independent of any particular 

 thickness being assigned to the earth's solid crust, or to whether there be 

 at present a liquid fused nucleus, all that is necessary being a hotter 

 nucleus than crust, so that the rate of contraction is greater for the former 

 than the latter. The author then points out that, as the same play of tan- 

 gential pressures has elevated the mountain-chains in past epochs, the 

 nature of the forces employed sets a limit to the height of mountain 

 possible of the materials of our globe. 



That volcanic action due to the same class of forces was more energetic 

 in past time, and is not a uniform but a decaying energy now. Lastly, 

 he brings his views into relation with vulcanicity produced in like manner 

 in other planets, or in our own satellite, and shows that it supplies an 

 adequate solution of the singular and so far unexplained fact that the 

 elevations upon our moon's surface, and the evidences of former volcanic 

 activity, are upon a scale so vast when compared with those upon our 

 globe. 



Finally, he submits that if his view will account for all the known facts, 

 leaving none inexplicable, and presenting no irreconcilable conditions or 

 necessary deductions, then it should be accepted as a true picture of 

 nature. 



"VIII. " On some Properties of Anhydrous Liquefied Ammonia." By 

 G. Gore, E.R.S. Received May 15, 1872. 



(Abstract.) 



This investigation was made for the purpose of ascertaining the general 

 solvent properties of the liquid, and to detect any manifest chemical re- 

 actions between it and various substances. The method employed was 

 precisely similar to that used in the examination of liquid cyanogen (see 

 Proc. Roy. Soc. No. 131, 1871), the tubes being charged with anhydrous 

 chloride of calcium previously saturated with the ammonia vapour. 



Two hundred and fifty substances were submitted to contact with the 

 liquid, and the general results in each case recorded. The only elementary 

 substances soluble in it were the alkali-metals proper, also iodine (bromine 

 was not tried), sulphur, and phosphorus. The more frequently soluble in- 

 organic salts were nitrates, chlorides, bromides, and iodides ; whilst oxides, 

 fluorides, carbonates, sulphides, and sulphates were very generally in- 

 soluble. Many saline substances, especially certain chlorides, bromides, 

 iodides, and sulphates, absorbed ammonia freely, and swelled greatly, but did 

 not dissolve. The behaviour of the chlorides of mercury was peculiar. 



Various compounds of carbon were submitted to the action of the solu- 

 tion of potassium in the liquefied vapour ; the free potassium disappeared, 

 but no elementary carbon was liberated. 



