316 The Spraying of Plants. 



must not be prolonged so that the heat would injure the germi- 

 native power of the seed. If the water is at a temperature 

 of 132| F., the spores will be killed, and yet the immersion, 

 if not continued beyond fifteen minutes, will not in the least 

 injure the seed. The temperature must be allowed to vary but 

 little from 132i, in no case rising higher than 135, or falling 

 below 130. To insure these conditions when treating large 

 quantities of seed, the following suggestions are offered : 



" Provide two large vessels as two kettles over a fire, or 

 boilers on a cook-stove, the first containing warm water (say 

 110 to 130), the second containing scalding water (132). 



" The first is for the purpose of warming the seed preparatory 

 to dipping it into the second. Unless this precaution is taken 

 it will be difficult to keep the water in the second vessel at a 

 proper temperature. 



" The seed which is to be treated must be placed, a half-bushel 

 or more at a time, in a closed vessel that will allow free entrance 

 and exit of water on all sides. For this purpose a bushel basket 

 made of heavy wire could be used, within which spread wire net- 

 ting, say twelve meshes to the inch, or an iron frame could be 

 made at a trifling cost, over which the wire netting could be 

 stretched. This would allow the water to pass freely and yet 

 prevent the passage of the seed. A sack made of loosely woven 

 material (as gunny sack) could perhaps be used instead of the 

 wire basket. A perforated tin vessel is in some respects prefer- 

 able to any of the above. 



" Now dip the basket of seed in the first vessel ; after a 

 moment lift it ; and, when the water has for the most part 

 escaped, plunge it into the water again, repeating the operation 

 several times. The object of the lifting and plunging, to which 

 should be added also a rotary motion, is to bring every grain 

 in contact with the hot water. Less than a minute is required 

 for this preparatory treatment, after which plunge the basket 

 of seed into the second vessel. If the thermometer indicates 

 that the temperature of the water is falling, pour in hot water 

 until it is elevated to 132^. If it should rise higher than 132, 

 add small quantities of cold water. This will doubtless be the 

 most simple method of keeping the proper temperature and 

 requires only the addition of two small vessels, one for cold 

 and one for boiling water. 



