Thorium fluoride, ThF 4, is obtained as a heavy white insoluble powder by dissolving the hydrate in hydrofluoric acid and evaporating.
By precipitating a thorium salt with a fluoride, a gelatinous hydrate, ThF 4.4H 2 O, is obtained.
Relation to the stars; in the planetary theory the origin is trans - ferred to the sun, and afterwards to the mass-centre of thf solar system; and so on.
The angle whose tangent is the coefficient of friction is called thf angle of repose, and is expressed symbolically by 4) tan_if.
In 1851 Lord Palmerstor proposed that the general line of frontier should be traced by thf agents of Turkey and Persia at Constantinople, assisted by th commissioners, in conformity with the treaty of Erzerum, leaving doubtful localities to be settled in future.