REPORT OF THE CHEMIST. 91 
vittata, &c.) and the nauseovs-smelling squash-bug, In short, it may 
be plainly stated that without the coéperation of certain birds, anima!s, 
&c., this country would be overrun with insect pests; and it has been 
found that in most cases wherever certain birds have been destroyed 
as injurious to some of the crops, the farmers have been overrun with 
grub-worms, wire-worms, &c., for years afterward, and have only been 
too glad to import again the very same species of birds for which they 
once paid so much per head to have destroyed. 
TOWNEND GLOVER, 
Fintomologist and Curator of the Museum. 
Hon. HoRAcE CAPRON, 
Commissioner. 
REPORT OF THE CHEMIST. 
Str: The work cf the laboratory during the year 186970 has been 
mainly of the same nature as during the preceding year. Theefforts to 
lessen the number of analyses of an unimportant nature in their bear- 
ing upon agricultural science, have been so far successful that the 
number accepted and performed has, for the first time, been within 
the means of the laboratory to complete; and the new year opened with 
no work remaining on hand exeept the general investigations which 
will extend at least over the ensuing year. This fact affords ground for 
the hope that the time is not far distant when all the efforts of the labo- 
ratory may be directed toward questions of vital and general importance. 
The analyses performed inelude a large number of mineral determina- 
tions, undertaken at the instance both of scientific men and explorers; 
assays of ores of the precious and other metals; analyses of soils, among 
which will be mentioned the alkaline soils from Nevada; maris, guano, 
marsh mud, peat, saline matters from the plains, artificial and natural 
fertilizers, not included in the above; wines, grapes; investigations 
made at the request of different States; proximate analyses of plants; 
cases of suspected poisoning, both of human beings and animals; Indian 
food materials; meat extracts; mineral waters; residues from the same; 
refuse from several manufactures ; and lastly the answering of a large 
number of letters of inquiry from farmers, brewers, and other sources 
upon questions touching the industrial arts and manufactures connecte 
with agriculture. This correspondence involves great labor, and the 
expenditure of much time. Itrequires a certain and extended acquaint- 
ance with the status of these arts at the present day, for which acquaint- 
ance much time is expended which would otherwise be bestowed on 
matters strictly connected with the laboratory. This function of the 
chemical division, although a severe tax upon it, is both beneficial to 
the farmer, and may be considered as but the discharge of a just debt 
incurred by the Department in obtaining, as it does, through its statis- 
tical division, invaluable information from the people. 
Besides the work already enumerated, the important investigation of 
the cereal crops which has been alluded to in the report for 1863, has 
been commenced. There have already been collected from various 
parts of the United States above seven hundred and fifty specimens, de- 
rived from over two hundred localities, of corn, wheat, rye, and oats, 
representing average crops in the several States and Territories, and 
raised under conditions so vastly different as regards climate, elevation, 
