Pyro-heat, mean

Synthesis from Acelyl Chloride.— As can be readily seen this is the simplest ketone acid that is possible and it is an alpha-V.tiont acid. Its name is derived from the fact that it is obtained from racemic acid by heat. It is a liquid boiling at 165°. Its constitution is best shown by the following syntheses. Acetyl chloride by means of silver cyanide yields acetyl cyanide which by hydrolysis gives pyro-racemic acid. 

Pyro-catechinol, i-2-Di-hydro3iy Benzene.—The ortho-di-hydroxy benzene is known as pyro-catechinol or pyro-catechin. The first name is preferable as the termination ol indicates its phenol character. Its name also indicates its relation to a resin known as catechu, obtained from an acacia tree. On distillation it yields the phenol, the prefix pyro meaning heat. It is also present in the dry distillation products of wood, coal or bituminous shale. Various plant materials such as resins and the leaves of ampelopsis yield it by alkali fusion. It is also associated with phenol as a sulphuric acid ester in the urine of horses. 

The prefix pyro means heat or fire. Pyrosulfuric acid may also be obtained by heating concentrated sulfuric acid, which results in the ehmination of one molecule of water fi-om two molecules of sulfuric acid. 

From the Greek pyro and phyllon, meaning fire and leaf , in reference to this mineral s behaviour when heated. 

A large number of metallurgical processes utilize high temperatures to alter the mineral chemically and to ultimately reduce it to the free metal. The use of heat to alter or reduce the mineral is called pyrometallurgy. Pyro means "at high temperature.")... 

I Pyrometallurgy contains the Greek stem I pyro, meaning fire or heat... 

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