ADDRESS. Ixxix 



be overrated. Their palo, I had almost said etiolated, faces are a sure indi- 

 cation of the absence of the vivifying influence of the solar rays, so essential 

 to the maintenance of vigorous health. The chemist can furnish a simple 

 test of this state of the atmosphere in the absence of ozone, the active form 

 of oxygen, from the air of our large towns. At some future day the efforts 

 of science to isolate, by a cheap and available process, the oxygen of the 

 air for industrial purposes may be rewarded with success. The effect of such 

 a discovery would be to reduce the consumption of fuel to a fractional part 

 of its present amount ; and although the carbonic acid would remain, the 

 smoke and carbonic oxide would disappear. But an abundant supply of puro 

 oxygen is not now witliin our reach ; and in the mean time may I venture to 

 suggest that in many localities the waste products of the furnace might be 

 carried off to a distance from the busy human hive hj a few horizontal flues 

 of large dimensions, terminating in lofty chimneys on a hillside or distant 

 plain ? A system of this kind has long been employed at the mercurial mines 

 of Idria, and in other smclting-works where noxious vapours are disengaged. 

 With a little care in the arrangements, the smoke wouH be wholly deposited, 

 as flue-dust or soot, in the horizontal galleries, and wonld be available for 

 the use of the agriculturist. 



The future historian of organic chemistry will have to record a succession 

 of beneficent triumphs, in which the efforts of science have led to results of 

 the highest value to the wellbeing of man. The discovery of quinine has 

 probably saved more human Ufe, with the exception of that of vaccination, 

 than any discovery of any age ; and he who succeeds in devising an artificial 

 method of preparing it will be truly a benefactor of the race. Not the least 

 valuable, as it has been one of the most successful, of the works of our 

 Government in India, has been the planting of the cinchona-tree on tho 

 slopes of the Himalaya. As artificial methods are discovered, one by one, of 

 preparing the proximate principles of the useful dyes, a temporary derange- 

 ment of industry occurs, but in the end the waste materials of our manufac- 

 tures set free large portions of the soil for the production of human food. 



Tho ravages of insects have ever been the terror of the agriculturist, and 

 the injury they inflict is often incalculable. An enemy of this class, carried 

 over from America, threatened lately with ruin some of the finest vine 

 districts in the south of France. The occasion has called forth a chemist of 

 high renown ; and in a classical memoir recently published, M. Dumas ap- 

 pears to have resolved the difficult problem. His method, although immedi- 

 ately applied to the PJujlIoawa of the vine, is a general one, and will no 

 doubt be found serviceable in other cases. In the apterous state the PJti/l- 

 loxera attacks the roots of the plant ; and the most efficacious method hitherto 

 known of destroying it has been to inundate the vineyard. After a long and 

 patient investigation, M. Dumas has discovered that the sulphocarbonate of 

 potassium, in dilute solution, fulfils every condition required from an insccti- 



