NEW DOSAGE TABLES 5 



have adopted it subsequently were not aware of the identity of their 

 method of calculation. The prevailing plan is to vary the dose at the 

 same rate as the tent area varies. That is, a ten-foot tree receives four 

 times as much as a five-foot tree and has four times as much tent area. 

 Each square foot of tent area by this plan may allow the same amount 

 of gas to escape before the tent is empty, no matter what the size of 

 the tree. 



How completely incorrect this plan is can be appreciated by extend- 

 ing the table to trees of very large size. The amount per cubic foot 

 is half as large in a ten-foot tree as in a five-foot tree and a quarter 



Fig. 2. Sizes of trees that receive 20, 7 and 2 oz. respectively. 

 The medium size tree has the same dose in all tables. At both 

 extremes the correct size is smaller than those given in the com- 

 mon tables, therefore the doses in the common tables are much 

 too weak. 



as dense in a twenty-foot, an eight in a forty-foot, etc. Evidently the 

 initial density will soon come to be so low as to be completely inefficient. 



The calculation of the dose by this method is not far wrong for 

 trees of medium size and the plan served a useful purpose as long 

 as there was nothing better, but it is now clearly time to discard what 

 was from the first given as a tentative makeshift to be used until a 

 better method was worked out. 



The method gives in fact doses that are too weak at both ends of 

 the table and most of the tables have been arbitrarily increased at the 

 lower end to accord with the experience of fumigators which has 

 abundantly shown the weakness of the calculated tables. 



The tables which follow give a much more accurate determination 

 of the doses and these are conspicuously different both for large and 

 for small trees as shown in Figure 2. 



