28 Scientific Proceedings, Royal Dublin Society. 



4. Tlie rate at which the "streamhig" proceeds depends largely, though not 

 wholly, upon the rate at which the concentration and cooling of the surface layer 

 of the water is brought about by evaporation from it. 



5. The process of " streaming," and consequently of mixing, also proceeds more 

 rapidly at temperatures at and above 10' 0. than below it. It is distinctly lets 

 ]'apid and less uniform downwards to 10 feet deep, and probably to greater depths, 

 at temperatures below 8° 0., especially in fresh waters. 



6. The rate at which the process of mixing from " streaming " proceeds also 

 depends upon the concentration of salt in solution. The optimum concentration 

 appears to be about 1 per cent, sodium chloride. 



This last conclusion is based upon one series of experiments only, and should 

 be confirmed by further experiments which the authors hope shortly to carry out. 



Chemical Division, 



EoYAL College of Science, 

 Dublin. 



