110 
visible. Bowls, graduates, and bisulphide were left with Mr. Taylor, 
and all the treated hills were marked for later examination and to note 
the effects of the chemical. The experiments were made in the middle 
of a very hot day, the thermometer 93° in the shade, little or no wind 
blowing, and the sand so hot that it burned through shoe soles and 
could scarcely be handled more than a few moments at a time. Many 
of the hills showed the edges of the leaves, when the covers were 
removed, yellowed and set with numerous drops of a clear liquid. I 
feared permanent injury, but instructed Mr. Taylor if he found that 
the plants died to continue his work before the sun was high or after 
it was quite low. He wrote me under date of July 19 : " The hills you 
treated when here last started to grow nicely, except the two hills 
where the carbon was poured on the ground; that killed them. The 
treated hills showed no lice at last examination." I am quite satisfied, 
from the experiments above recorded and from others that were not 
recorded, but were simply made to settle practical questions, that in 
melon fields at least bisulphide of carbon can be used satisfactorily and 
effectively. It has the enormous advantage of reaching everything on 
all parts of the plant , not a specimen escaping. With a stock of from 
50 to 100 light covering-boxes about 18 inches in diameter, as many 
shallow dishes, and a bottle of bisulphide the infested hills in a field 
<?an be treated in a comparatively short time. 
Mr. South wick coincided with the author of the paper in the impor- 
tance and value of prompt preventive measures, and stated that he was 
especially interested in the use of bisulphide of carbon, which he had 
employed in his work in Central Park since 1884. He referred to a new 
wash, a combination of bisulphide with " poly solve, " which he used in 
the form of an emulsion. He stated, however, that "polysolve" was 
no longer being manufactured, but thought its place might be taken by 
kerosene emulsion. In reply to a question by Mr. Lintner, Mr. Smith 
stated that he had made his experiments when the runners had reached 
a length of 5 or 6 inches, and he urged a prompt use of the insecticide 
on the first appearance of the lice. Mr. Lintner suggested the use of 
<?loth coverings, in lieu of the heavier and more clumsy wooden boxes. 
Prof. Galloway said that the formation of globules of liquid on the 
leaves, referred to by Mr. Smith, was due to the reduction of temper- 
ature caused by the evaporation of the bisulphide, and that this source 
of possible injury might be avoided by making the applications in the 
early morning or late in the evening, when the surrounding temperature 
was much lower. He referred also to the protection cloth which is used 
by seedsmen, and which is treated with oil so as to be practically air- 
tight, and suggested its use for coverings, in lieu of wooden boxes or 
Ibowls. Mr. Smith stated that some of the boxes used by him were very 
