IXXX. REPORT 187G. 



cide, clcsfcro_yiug tlic insect without injuring the jjlant. The process required 

 time and patience ; but the trials in the vineyard have fully confirmed the 

 experiments of the laboratory. 



The application of artificial cold to practical purposes is rapidly extending ; 

 and, with the improvement of the ice-machine, the influence of this agent 

 upon our supply of animal food from distant countries will undoubtedly be 

 immense. The ice-machine is already employed in paraffin-works and in 

 large breweries ; and the curing or salting of meat is now largely conducted 

 in vast chambers, maintained throughout the summer at a constant tempera- 

 ture by a thick covering of ice. 



I have now completed this brief I'evicw, rendered difficult by the abun- 

 dance, not by the lack of materials. Even confining our attention to the 

 few branches of science upon which I have ventured to touch, and omitting 

 altogether the whole range of pure chemistry, it is with regret that I find 

 myself constrained to make onlj- a simple reference to the important work of 

 Cayley on the Mathematical Theory of Isomers, and to elaborate memoirs 

 which have recently appeared in Germany on the reflection of heat- and light- 

 rays, and on the specific heat and conducting-powcr of gases for heat, by 

 Knoblauch, E. "Wiedemann, "Winkelmann, and Buff. 



The decline of science in England formed the theme, fifty years ago, of nn 

 elaborate essay by Babbage ; but the brilliant discoveries of Faraday soon 

 after -wiped oft' Ihe reproach. I will not verdure to say tliat the alarm which 

 has lately arisen, here and elsewhere, on the same subject will prove to 

 be equally groundless. The duration of every great outburst of human 

 activity, whether in art, in literature, or in science, has always been short, 

 and experimental science has made gigantic advances during the last three 

 centuries. The evidence of any great failure is not, however, very manifest, 

 at least in the physical sciences. The journal of PoggcndorfF, which has long 

 been a faithful record of the progress of jAysical research thi'oughout the 

 world, shows no signs of flagging; and the Jubelband by which Germany 

 celebrated the fiftieth year of Poggendorff"s invaluable services was at the 

 sarao time an ovation to a scientific veteran, who has perhaps done more 

 than any man living to encourage the highest forms of research, and a proof 

 that in Northern Europe the physical sciences continue to be ably and 

 actively cultivated. If in chemistry the case is somewhat weaker, the ex- 

 planation, at least in this country, is chiefly to be found in the demand on 

 the part of the public for professional aid from many of our ablest chemists. 



But whatever view be taken of the actual condition of scientific research, 

 there can be no doubt that it is both the duty and the interest of the country 

 to encourage a pirrsuit so ennobling in itself, and fraught with such impor- 

 tant consequences to the weUbeing of the community. Xor is there any 

 question in which this Association, whose special aim is the advancement of 

 science, can take a deeper int( rost. Tb.o public rnii'd has also been awakened 



