1907] Rain and Snow. 175 



In this connection it was stated that from recent analyses of 

 the rain as it fell on the Strand, in the heart of the City of 

 London, it had been computed that no less than 3,738 tons of 

 impurities (soot, salts of ammonia, etc.) had been washed out 

 of the atmosphere above London (greater London comprises 

 about 75,000 acres) in less than a week. Of course, the air of 

 our Canadian cities is much cleaner than that of London one 

 reason being that we burn anthracite, whereas in London soft 

 coal is used but these figures are significant in indicating what 

 rain can do in purifying the atmosphere. 



The relative humidity of the air plays an important part in 

 the maintenance of health. The humidity of the air is. of course, 

 directlv regulated or controlled bv the temperature, but the 

 source of the moisture which furnishes the air with aqueous 

 vapour is in the water that falls as snow and rain and rises again 

 by evaporation. 



Water supplies, both large and small, from lake, river and 

 well, must all depend on the fall of rain and snow. A season of 

 drought means not only poor crops, but wells almost dry. In 

 countrv villages, especially, does this low water mean typhoid 

 fever. Over and over again has it been observed that an exces- 

 sivelv clrv autumn reduces the crop yield of the following year, 

 imless the average precipitation is brought up by heavy rains 

 the next spring and not only this, but that sickness follows 

 quicklv in the train of drought. Stagnant water is impure water ; 

 the rain and the snow, as part of the cvcle which the water of 

 the earth performs, serves not only to give tis our water supplies, 

 but to keep them pure and wholesome. 



ARCEUTHOBIUM PUSILLUM (Peck). 



Arceuthobium pusillum is apparently widely spread through- 

 out Ontario, and in some places is doing serious mischief. Wherever 

 it occurs it is to be found in abundance, most of the branches 

 of the agrasitized tree being covered with it. Specimens of 

 A. pusillum on Picea nigra were first brought to me for identifi- 

 cation bv Mr. C. G. Eraser, one of mv students. They were 

 cohectedat Wilcox Lake, York County, by Messrs. S. R. Thomp- 

 son and C. G. Fraser. Later .further collections of stammate 

 and pistillate plants were secured at Snelgrove by Messrs. Jas. 

 and J. H. White, bv mvself at Wilcox Lake and at several points 

 in and near Algonquin Park, and by Mr. Bartlett, the Super- 

 intendent in Algonquin Park. The presence of this dwarf 

 mistletoe is at once evident by the "witches' brooms" it occasions. 

 It is likewise verv destructive to the life of the tree. 



J. H. Faull. 



