110 AXXl'AL KKPOHTs OK hKPART.MKXT OF AflBEOUUFDK 1940 
TOXK 11V OF Ni:w INSECTM EOAL ( OMPOl NDfl to GOLDFISH 
A study of the influence of temperature in the method used for 
determining the toxicity of insect icidaJ materials to goldfish was fin- 
ished during the year. The study was conducted with mo-nom- and 
phenol, because these 2 compounds have been used often as standards 
of comparison with other compounds. Five temperatures between 
7° and 27 C. were chosen. The minima] product of concentration 
and time, upon which all the conclusions in this work are based, has 
been estimated with a standard error of 2 to 4 percent for phenol and 
5 to U percent for rotenone. Despite the fact that the minimal product 
for rotenone is some 500 times that for phenol, the relationship be- 
tween the two remains practically constant. The toxicity of either 
compound is an experimental function of the temperature: a 1<> rise 
in temperature results, on an average for both compounds, in a J. 7-fold 
increase in toxicity. 
Of the mononitrophenols the ortho compound is the least t<>xie 
to goldfish; The meta compound is nearly twice a- toxic and the para 
compound about 5 times as toxic as the ortho compound. Rotenone i- 
•250 times as toxic as o-nitrophenol. The relative toxicity of the chloro- 
phenols as compared with phenol was found to be: Ortho. 1.15; meta. 
1.51; and para. 1.89. 
ANALYTICAL INVESTIGATIONS 
The analytical work of the Division embraced, as usual, the analysis 
of experimental samples being tested by other divisions of the Bureau. 
Nearly "•><> such samples were received. In addition, about 750 -oil 
samples from nurseries were analyzed for the Division of Japanese 
Beetle Control to see whether they should be retreated with lead ar- 
senate to bring them up to the minimum quarantine requirements. 
The Division took part as usual in the activities of the Association 
of Official Agricultural Chemists, conducting for them the collabora- 
tive testing of a method for minute amounts of arsenic developed in 
the Division, and of methods for the preliminary digestion of such 
organic matter, notably tobacco and shrimp, that has proved difficult 
to handle by the ordinary sulfuric and nitric acid digestion. Collab- 
orative testing of a method for determining methoxyl in lignin and 
rotenone was done by the member of the Division who i- the associa- 
tion's referee on microcheniical methods. 
.Method- for determining micro amounts of nicotine were perfected, 
one of which depends on measurement of the turbidity produced with 
phosphotungstic acid. The influence of various impurities on the 
colorimetrie test involving cyanogen bromide and /i-napht h via mine 
was studied, and the method adapted to the stud}/ of the nicotine con- 
tent of single green leaves of growing tobacco, which will be of 
assistance in tobacco breeding experiments. 
A method was developed for determining the residues of antimony 
left on citrus trees treated with tartar emetic for control of the citrus 
t hrips. Tentative procedures were also developed for residues of 
copper resulting from the use of copper-containing rungicides in 
coaling moth control. Efforts to find a micro method suitable for 
determining residues of xanthone, a new organic insecticide, were 
unsuccessful. 
