THE IMPROVED SYSTEM IN I 67 
variations aa may be found to exist are so small thai in practical 
work in the field the results in lulling scale-insects, from the use 01 
part of the table, will be found as satisfactory as from the use "1" 
any other part. Moderately heavy dosages almost invariably burn 
the tender shoots of a tree to a greater or Less extent. Under this 
schedule practice has demonstrated that the tender growth is uni- 
formly burned Hack in all cases, whether Large trees or small ones 
are fumigated. 
As previously stated in this discussion, dosage schedule No. l 
was prepared for use against the purple scale at Whittier, Cal., during 
the Latter part of July when the fruits in some orchards were about 
the size of a walnut. The dosage employed was as great as the fruit 
would permit at that season without injury. This does not indicate 
that a Larger dosage can not he safely used at other -c;i^<>!i> of the 
year, if desired. The writer has at times employed a dosage of 
double the strength without visible injury to the trees. This was 
accomplished, however, under more favorable conditions, during the 
fall and winter months, when the fruit was well grown. It is UOt 
deemed advisable to use a dosage against the purple scale of less 
strength than that of schedule No. 1. If complete eradication is 
desired, a much heavier dosage must necessarily he employed. 
The dosage in schedule No. 1 is equivalent to what i> known among 
many fumigators as the "double dosage." It may be a little stronger 
than the double dosage of some, rather than weaker. "Double 
dosage" is usually intended to signify a dosage twice the strength 
required to destroy the black scale in its earlier stages. 
Since this schedule is one of uniformity, it readily permits of 
manipulation. If a heavier dosage should be desired, such may he 
obtained by increasing each individual number or dosage in thesame 
ratio: if a lighter dosage, by proportionately decreasing each. The 
schedule resulting from such increase or decrease will also he one ■)( 
the same general uniformity as the first. The writer has prepared 
schedules which are \, |, 1J, 1J, and \\ times the dosage indicated 
in schedule No. 1 . 
THE IMPROVED SYSTEM IN USE. 
Two outfits of the Whittier (Cal.) Citrus Association commenced 
the use of this improved system of fumigation, with dosage schedule 
No. 1 . during the latter part of July, 1908. The apparent uniformity 
of work, indicated by the evenness with which the tender growth 
was burned hack on all trees, immediately attracted the at lent ion 
of citrus growers who >;i\\ the fumigated orchard-. Their universal 
approval of the method i> shown \)\~ the fact that not a single unfa- 
vorable comment was brought to the writer's attention throughout 
the entire fumigation work. The reception of an improved method 
