Antimony and its compounds formed the subject of an elaborate treatise ascribed to this last writer, who also contributed to our knowledge of the compounds of zinc, bismuth and arsenic. All the commonly occurring elements and compounds appear to have received notice by the alchemists; but the writings assigned to the alchemical period are generally so vague and indefinite that it is difficult to determine the true value of the results obtained.
The best proof that King Henrys orderly if autocratic rgime was appreciated at its true value by his English subjects, is that when the second series of rebellions raised by his undutiful sons began In 1182, there was no stir whatever in England, though in Normandy, Brittany and Aquitaine the barons rose in full force to support the young princes, whose success would mean the triumph of particularism and the destruction of the Angevin empire.
The census estimate of the true value of property constituting the national wealth was limited in an enumeration of 1850 to taxable realty and privately held personalty; in 1900 it covered also exempt realty, government land, and corporation and ptiblic personalty.
Boiamund proposed to assess the tax, not according to the old conventional valuation but on the true value of the benefices at the time of assessment.
In the case of mathematical functions certain conditions of continuity are satisfied, and the extent to which the value given by any particular formula differs from the true value may be estimated within certain limits; the main inaccuracy, in favourable cases, being due to the fact that the numerical data are not absolutely exact.