DIVISION OF CHEMISTRY 265 



SESSIONAL PAPER No. 16 



for examination to ascertain if they are equal to the guarantee. In the majority of 

 instances these have been foimd of guaranteed strength, but in a few cases they have 

 been weaker. We advise that on the labels, in addition to directions for use and the 

 caution to be observed in its employment in order to avoid the poisoning of children 

 and stock, tbe amount of strychnine per fluid ounce be stated. 



Strychnine and strychnine sulphate are white, crystalline solids, but may be 

 brought into solution by the addition of a few drops of acid or a little strong vinegar. 

 Strychnine sulphate is fairly soluble and for this reason is, perhaps the better form 

 to use, when the solution is not bought. In employing either of these substances, 

 the poison should be entirely dissolved before covering the grain with the solution. 

 All the samples of strychnine and strychnine sulphate (crystallized) submitted to 

 analysis have been found pure. The quantity usually recommended is one ounce 

 of strychnine to one bushel of wheat. 



The wheat should be allowed to stand in the poison solution (of which there 

 should be sufficient to cover the grain) for 36 hours, or until the grain is quite soft, 

 showing thorough saturation with the poison. A teaspoonful placed at the mouth 

 of each burrow should be ample. 



We would again emphasize the necessity for the greatest care in the handling 

 and use of this deadly poison, to avoid accident. 



THE FERTILIZING VALUE OF EAIN AND SNOW. 



The sixth year of this investigation, the object of which is to ascertain the possible 

 enrichment of the soil, per acre, due to nitrogen compounds furnished by rain and 

 snow, closed on February 28, 1913. The collection of the samples submitted to 

 analysis has been made on the Central Experimental Farm, situated on the outskirts 

 of Ottawa, and every precipitation of rain and snow that would yield a sufficiency for 

 analysis from the catchment area employed has been chemically examined* 



In previous reports we have dealt at some length with the various factors that 

 influence the nitrogen-content of the precipitation' — and especially that of the rain. 

 It may, therefore, suffice to enumerate the more important of these and to state briefly 

 that the total amount of nitrogen so furnished per acre, per annum, has not been 

 found to follow the total precipitation closely. 



While the direction of the prevailing winds, considered apart from velocity 

 during the falling of rain and snow, as for instance toward or from the city, does not 

 apparently markedly influence the nitrogen content, its velocity or violence may and 

 frequently does very appreciably affect the character of the rain in this respect. The 

 rain during thunder storms is invariably rich in nitrogen, and this we have attributed 

 chiefly to the presence of an increased amount of dust in the air, though to some 

 extent the nitrates may be increased by the electric discharges (lightning flashes) of 

 the storm. It has been repeatedly noted that the rain falling during or immediately 

 following cyclonic storms of great severity and which ' filled ' the atmosphere with 

 dust particles, had an exceedingly high nitrogen-content, more particularly present 

 as free and albuminoid ammonia. 



Another factor and probably the most potent, is frequency of precipitation, and 

 this is more particularly true during the summer months. A scanty rainfall after 

 a period of hot, dry weather, is invariably rich, and on the other hand the later collec- 

 tions after several days of showery weather show a rapidly decreasing nitrogen-content. 



During the year March 1, 1912, to February 28, 1913, 107 samples were collected 

 and analyzed, being fifteen more than the year previous. 



•The catchment basin is approximately 60 by SO inches, and is placed about 25 feet from 

 the ground, which, for some distance around, is in lawn and shrubbery. 



