96 



An important and practical bulletin of the Bureau of Plant In- 

 dustry of the U. S. Department of Agriculture has recently been 

 issued under the title of " A [Method of destroying or preventing 

 the Growth of Algae and certain pathogenic Bacteria in Water 

 Supplies," the authors being Dr. George T. Moore and Mr. Karl 

 F. Kellerman. The following statements are quoted from the 

 authors' summary : "It has been found that copper sulphate in 

 a dilution so great as to be colorless, tasteless and harmless to 

 man, is sufficiently toxic to the algae to destroy or prevent their 

 appearance. The mode of application makes this method ap- 

 plicable to reservoirs of all kinds, pleasure ponds and lakes, fish 

 ponds, oyster beds, water-cress beds, etc. It is also probable 

 that the method can be used for the destruction of mosquito 

 larvae. At ordinary temperatures i part of copper sulphate to 

 100,000 parts of water destroys typhoid and cholera germs in 

 from three to four hours. The ease with which the sulphate can 

 then be eliminated from the water seems to offer a practical 

 method of sterilizing large bodies of water, when this becomes 

 necessary." Reservoirs have been successfully treated by towing 

 the copper sulphate in a coarse bag from the stern of a row-boat. 

 A solution of i part of the sulphate to about 50,000,000 parts of 

 water has been found fatal to Spirogyra and a i to 4,000,000 

 solution appears to be destructive to the blue-green algae. 



The Philadelphia Botanical Club and the Torrey Botanical Club 

 will hold a joint field meeting at McCall's Ferry, Pennsylvania, in 

 the valley of the Susquehanna River, July 2 to 9, 1904, which 

 all botanists are cordially invited to attend. Excursions will be 

 made from this point as a center, to points in the vicinity, return- 

 ing each day ; botanists can therefore conveniently take pf^rt in the 

 meeting by arriving at McCall's Ferry any afternoon during the 

 week. Informal evening conferences will be held for the discus- 

 sion of topics that may be brought forward. Fares to McCall's 

 Ferry are as follows : Philadelphia to McCall's Ferry and return, 

 S3. 36; New York to McCall's Ferry and return, $6.96 ; Wash- 

 ington to McCall's Ferr>' and return, $4.06. Hotel charges at 

 McCall's Ferry are $1.25 per day. Guides : Messrs. Stewardson 

 Brown and Jos. Crawford. 



