198 
BUI^IyETlN OF THE BUREAU OF FISHERIES. 
SUMMARY. 
1. The fluidities of fish and vegetable oil mixtures are additive, except where 
there is decomposition of either component on heating. 
2. The viscosities of these mixtures are also additive when the values for the com- 
ponents approximate each other closely. 
3. The fluidities of vegetable oils are nearly linear functions of the temperature. 
It has been previously shown that this holds true for various fish oils. 
4. The fluidity of China-wood oil is a good test of its purity, as it is unusually low. 
5. The specific gravities of the mixtures are approximately additive and vary lin- 
early with the temperature. The density of China-wood oil is very high. 
6. The index of refraction, acid number, and saponification number of the mixtures 
do not allow any general conclusions. The acid number of linseed oil is high and that 
of dogfish-liver oil is low compared with that of China-wood oil. The refractive index 
of China-wood oil is lowered by the introduction of small amounts of fish oil. 
7. The low iodine number of the dogfish-liver oil makes the presence of this oil in 
vegetable oils known by marked lowering of their iodine values. 
