210 ANNUAL OF SCIENTIFIC DISCOVERT. 



GRIFFIN'S THEORY OF CHEMICAL RADICALS. 



Mr. Griffin, the well-known chemical writer of England, has published, 

 during the past year, a new chemical theory of radicals, upon the elaboration 

 of which, he states, he has spent thirty years of his life. The following is 

 a general abstract of its principal points. 



" Every salt is composed of two radicals, simple and compound, oxidized 

 or not oxidized. 



" Every element can act as a radical except oxygen. Oxygen never acts as 

 a simple radical, nor forms part of a compound radical. Some of the 

 metallic elements form two radicals, which differ in weight and properties. 



"Compound radicals consist of (1) carbon and hydrogen, or (2) carbon and 

 nitrogen, or (3) combinations of other elements with the foregoing. 



" The quantity of an element which constitutes a radical is an atom, or as 

 much as forms a single volume of gas. 



' The quantity of a compound which constitutes a radical is as much as 

 forms a single volume of gas. When the compound is not gaseous, the 

 radical quantity is as much as is equivalent to a single volume of hydrogen 

 or chlorine. 



" Every gaseous salt measures two volumes, which is the measure of its 

 two radicals. When salts contain oxygen, that element adds to their weight, 

 but not to the measure of their gas. 



" Though a compound radical, that measures one volume in the state of 

 gas, still measures one volume when combined with one or more atoms of 

 oxygen, the oxygen is not to be considered as a constituent part of the radi- 

 cal, but only as an addition to it. 



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" Since all gaseous salts that contain two radicals form two volumes of gas, 

 whether the radicals are simple or compound, oxidized or not oxidized, it is 

 assumed that every compound radical, if isolated and brought into the 

 gaseous state, would measure one volume. 



******* 



" Salts combine with one another, so as to form double, triple, quadruple, 

 and other forms of compound salts." 



ON THE DETERMINATION OF THE VALUE OF PRECIPITATES. 



M. Mene, of France, has communicated to the Academy a new mode of 

 determining the numerical value of precipitates in chemical analysis. The 

 common practice, when proportional solutions cannot be made, is to drive 

 off the water with which the precipitate is impregnated by calcination, sand- 

 baths, or other contrivances which take much time. M. Mene simply 

 washes his precipitate by decantation, and then introduces it into a gradu- 

 ated phial, which he afterwards weighs. The precipitate is then taken out, 

 and the phial, filled with water to the same degree, is again weighed ; when 

 the difference of the two results gives the exact weight of the precipitate. 



ARTIFICIAL PRODUCTION OF GEMS AND OTHER MINERALS. 



The late M. Ebelman suggested the ingenious method of producing the 

 gems of the corundum family (sapphire, ruby, hyacinth, etc.,) by fusing the 

 alumina with an excess of boracic acid, and then suffering the solvent to 



