8 



Heatins: Grcrn-houscs. 



My microscopic investigations have been attended with some diffi- 

 culty. A h^rge magnifying power of my instrument was requisite to 

 resolve the fungus into its parts, and examine them by detail. The 

 general appearance of the growth, whether on leaf or berry, was that 

 of jungle of colorless transparent vegetation, and the nicest manipula- 

 tion was necessary to get a single stem so placed under the lens, that, 



Fig. 3- 



even with facilities for delicate changes in the adjustment of the focus, 

 the whole of its length could be passed before the enlarged vision. 



I have not prepared this brief article with any purpose of disputing 

 the method of treatment advocated by Mr. Flagg, because there is a 

 difference in the fungi. On the contrary, if sulphur be not the remedy, 

 I do not know what can be relied upon. 



July 31, 1870. 



HEATING GREEN-HOUSES. 



By W. C. Strong, Brighton, Mass. 



Plants do not keep warm by exercise. We have no method of 

 preserving the excessive heat of the sun, as we do the cold of winter, 

 to retad in small crvstal blocks during the hot days of summer. Dur- 

 ing the stormy days of winter the sun's rays are an uncertain quantity. 



