CHESTNUT BARK DISEASE. 445 
like to know if the blight on the whole, without regard to 
treatment in checking it, has spread as seriously in Pennsylvania 
during the past year as it did in 1911. So far as Connecticut 
is concerned, there seems to be a decided improvement, if we 
can judge by the reports that we have received.” 
In answer to this letter, under date of March 1, 1913, Carle- 
ton wrote as follows: “I have your letter of February 28th, and 
in reply will say first, that the reports in the papers about the 
spraying with Bordeaux mixture in connection with chestnut 
blight were, as usual, much exaggerated, and in some respects 
quite erroneous. The use of Bordeaux mixture is, at most, 
only a preventive, though the papers reported it to be a cure. 
Of course, as you know, nothing will cure the disease after it 
is in the tree. The Bordeaux was used on the estate of Pierre 
DuPont near Kennett Square. In connection with tree surgery 
methods, and by spraying about every two weeks during the 
summer, these two methods taken together appear to have con- 
trolled the blight. It is believed that the Bordeaux mixture was 
of great use in preventing the germination of spores on healthy 
trees, and on healthy portions of trees that were being treated. 
I believe the spraying with Bordeaux is of sufficient importance 
in chestnut orchards to recommend its practice in all cases of 
chestnut blight. It might be used, also, on unusually valuable 
lawn trees, but of course, it would be impracticable in forest 
tracts, chiefly on account of the cost, and for other reasons. 
“As to the spread of the blight in Pennsylvania, I regret to 
say that over a large portion of the state it has apparently 
spread more rapidly than the year before, so that the conditions 
appear, therefore, to be different from those in Connecticut, 
according to your statement. Because of the condition last 
stated, of the serious increase of the disease in this state, and 
particularly in those portions west of the Susquehanna, where 
we are endeavoring to check its progress, you can see that our 
work has been unusually difficult. Answering your question, 
however, as to our success in actually checking the blight, so far 
as we can get evidence one way or the other at all in the short 
time that I have been in the state, I believe we have accom- 
plished a great deal in that line. We can only actually know 
next summer, when we re-scout the areas over which cutting 
was done this summer. So far, in the areas of removal which 
