Ixviii. PRESIDENT'S ADDRESS. 



as other necessaries hitherto imported, will be successfully 

 made and used in our factories. The manufacture of many 

 pure chemicals and synthetic drugs is in a similar condition, 

 and some are almost unattainable now that the German 

 source of supply is closed. Phenacetine and some others 

 havr. however, already been made here, and steps are being 

 taken to supply the others needed. It is very desirable in 

 thi> connection that alcohol should be allowed duty free 

 with proper restrictions to the research chemist, as methylated 

 spirit is not suitable for many processes. It is now possible 

 chemically greatly to improve weak flour, so that it shall 

 work better, absorb more water, and give a larger loaf of 

 lighter texture. The address of the President of the Chemical 

 Section of the British Association dealt with the structure of 

 crystals and their chemical constitution, on which some 

 light has been thrown by the discovery of the wonderful 

 results produced by the passage of X-rays through crystals 

 alluded to in my address last year and by other recent 

 investigations. It has been found that a mixture of hydrogen 

 and oxygen is detonated by the radium emanation, forming 

 water. Some experiments, in which immense pressures 

 were used up to something like 200 tons to the square inch, 

 shew that the accepted theories of the melting of liquids 

 do not hold at high pressures, and it would seem probable 

 that a liquid can be frozen by sufficient pressure, at any 

 temperature. Several new solid forms have been obtained, 

 especially forms of ice which are denser than water. Many 

 new members have been recently added to the disintegration 

 series of radium, and it is considered that this series is now 

 nearly complete. 



ENGINEERING. 



The subject of aviation, with which I often begin my 

 notes on engineering, has been very forcibly brought to our 

 notice by the way in which it has altered the character of 

 warfare and rendered it most difficult to carry out any strategic 



