DOSAGE SCHEDULES OF MOEE IMPOKTANT WRITERS. 



19 



in excess of 20 ounces in a 2-gallon generator, the contents will fre- 

 quently boil over, especially if the cyanid is in small lumps or is 

 powdered. 



DOSAGE SCHEDULES OF THE MORE IMPORTANT WRITERS ON FUMIGATION. 



Since the publication by Morse, in 1887, of the first dosage schedule 

 for use in fumigating citrus trees with hydrocyanic-acid gas, a great 

 many tables of 

 dosage have been 

 re c o m mend e d 

 through publica- 

 tions in this coun- 

 try and abroad. 

 Among the more 

 authoritative 

 contributions on 

 this subject are 

 those of Coquil- 

 lett, Morse, Craw, 

 Marlatt, Johnson, 

 Havens, Wood- 

 worth, Pease, and 

 Morrill, of this 

 country; C. P. 

 Lounsbury, of 

 South Africa, and 

 W. J. Allen, of 

 New South Wales. 

 A careful study 

 has been made of 

 the dosage sched- 

 ules proposed by 

 these different in- 

 vestigators with a result most surprising. In the first place, we 

 must consider that uniform dosage will not be given to trees 

 unless based directly on their cubic contents when covered with 

 a tent. Secondly, dosage tables prepared for trees merely with 

 regard to their cubic contents and without regard to the varying pro- 

 portions of leakage surface present in trees of different sizes are 

 faulty to a large degree. Of all the dosage tables which have come 

 to the writer's attention only those by Lounsbury, in South Africa, 

 by Morrill, in Florida, and a recent one by Woodworth in California, 

 have been based on the proper assumptions. The other tables were 

 either based directly on the cubic contents without regard to leakage 

 surface, or were prepared without any knowledge whatever of the 

 cubic contents represented by trees of given dimensions. Several 



Fig. '.I.— Man carrying tray and water bucket. (Original.) 



