ORGANO-METALLIO BODIES. tinder this term are included a large number of chemical compounds in which organic radicals, such as methyl ethyl (C,II,), etc., are united •to metals in the same way as chlorine is combined with zinc, forming chloride of zinc. If, for instance, in chloride of zinc (ZuCl) we replace the chletine by ethyl, we produce one of the bodies belonging to this class, viz., zinc-ethyl, Zn(C,H.). This substance (which we take as a good example of the class) is obtained by digesting a mixture of equal volumes of iodide of ethyl and ether with granulated zinc, at a tem perature of about 260', for several hours. Subsequent distillation gives a mixture of zinc-ethyl and ether, from which the former may be obtained pure by rectification, in the form of a colorless, transparent, mobile liquid, which refracts light strongly, has a powerful but not disgreeable odor, and is rattier heavier than water, its specific gravity being 1.182 at 64'. 'With the exception of cacodyl, these bodies arc the
creatiou of the last ten or twelve years, during which period numerous compounds of organic radicals with zinc, cadmium, magnesium, antimony, arsenic, bismuth, mercury lead, sodium, and potassium have been discovered.
For further information on this subject the reader is referred to an article by Dr. Frankland (who has most successfully devoted his attention to this class of compounds) in the 13th vol. of The Quarterly Journal of the Chemical Society, and to an elaborate -article on " Organo-Metallic Bodies" (by the same chemist) in The English Cyclopadia.
or PEDAL-POLNT, in music, a bass note sustained through a series of chords, with only the first and last of which it is in harmony. The sustained note may be the dominant or tonic, and sometimes occupies an upper part instead of the bass.