12 



one of our home industries has lately been adopted, namely the 

 preservation of butter for a lengthened period by means of salicylic 

 acid. A very small portion of the acid is dissolved in two parts of 

 lactic acid and ninety-eight parts of water ; this mixtute is used in 

 the proportion of one grain of salicylic acid to one hundred kegs of 

 butter, and will keep the latter fresh for an almost indefinite 

 period. 



In my last annual address I mentioned the sponge industry at 

 Gratz. Since then an hiteresting report has been issued of the 

 sponge farms of Cuba, in which it appears that the demand of these 

 sponges is likely to be an increasing one. They do not, of course, 

 equal the fine Turkey sponges in texture, yet they are largely 

 employed in damping tobacco, and also in cleaning the machinery 

 in use on the sugar estates. In the Isles of the Bahamas, poeti- 

 cally termed the " land of the pink pearl," the sponge farms alone 

 give occupation to upwards of five thousand people. In Florida, 

 too, successful experiments of sponge growing have been made, 

 but the chief drawback to this industry is, that under the most 

 favourable circumstances, the farmer must wait five or even seven 

 years before his first crop is available. Therefore sponge farm- 

 ing, like tree planting, may be considered somewhat " an heroic 

 culture ! " 



Photography, which is both a science and an art, held what may 

 be called its Jubilee exhibition last March at the Crystal Palace. 

 Could Col. Daguerre and Fox Talbot themselves see the vast strides 

 this art has made since their day, they would indeed feel proud to 

 have inaugurated an art which has attained such superb results, 

 both artistically and scientifically. The perfection of the photo- 

 graphic instruments, and the artistic merit of the pictures exhibited, 

 called alike for the highest praise. The little floating magnesium 

 lamps have improved, and form a valuable and ready means of 

 taking views independently of sunshine. In connection with this 

 elaborate photographic display, a special feature was the admirable 

 finish of the oxyhydrogen lanterns for exhibiting many of the 

 photographs. The high pressure of 3,C001bs. to the square inch, 

 by which the gases are now forced into steel tubes to supply the 

 light, is reduced by a simble appliance in the jet, which impinges 

 on the hard lime wick, giving a small but most intense light, and 

 one eminently suit-jd for lantern lenses. The screen too on which 

 the views were presented is prepared m a novel manner, by cover- 

 ing the canvas with an enranel of white zinc paint, which prevents 

 the woven texture showing through the smooth surface, and thus 

 much enhances the clearness and beauty of the views. 



There is no scientific point which is still undergoing more search- 

 ing investigation than that of the influence of bacteria, and vaiious 



