250 THE ANALYST. TOXICOLOGICAL ANALYSIS. Estimation of Arsenic in Toxicology. G. Todeechini. (Boll. chim. farm., 1902, xli., 185 ; through Chem. Zed. Rep., 1903, 141.)-From experiments on flesh, to which known amounts of arsenic trioxide had been added, the author finds that Gautier’s process for the determination of arsenic, even when the improvements recommended by its inventor in 1899 are made use of, only returns one-third of theTHE ANALYST. 251 arsenic in the form of a mirror, the other two-thirds being lost. This loss is due to the fact that the carbonaceous residue retains much of the arsenic inma, form insoluble in water ; while if the said residue is warmed, partial reduction of the wsenic acid to arsenious acid occurs, and the latter volatilizes. When Gautier's solution is treated with sulphuretted hydrogen all the arsenic is not precipitated, probably because destruction of the organic matter is incomplete. Selmi's process is better, as only one-half the arsenic is lost, F.H. L. Selmi's Frocess for the Determination of Arsenic i n Toxicology. G. Giudice. (Gazz. chim. Ital., 1902, xxxii. [l], 164 ; through Chem. Zeit. Rep., 1902, 141.)-In using this process, if the apparatus is put together with rubber corks or tubes containing antimony sulphide, considerable quantities of antimony accompany the arsenic in the cold receiver, even if the temperature of the oil-bath in which the retort and first receiver are placed does not exceed 130" C., so that the mirror may consist in large part of antimony instead of arsenic. If the material under examina- tion contains antimony compounds, antimony will contaminate the arsenic if the temperature is allowed to reach 130" C., but will not enter the cold receiver provided the oil-bath is kept below 115" C. Mercury and tin salts do not affect the working of Selmi's process, as they are not driven over even at a temperature of 130". F. H. L.