I. Introductory. Ever since the discovery of glucinum by Vauquelin, in 1798, its atomic weight has been a disputed matter amongst chemists. Its discoverer considered that its oxide was a monoide, an opinion which was however strongly opposed by Berzelius, who wrote the oxide Gl
2
O
3
and the atomic weight 13⋅7 (O=16). The researches of Awdejew and Debrayt again turned the scale in favour of the earlier view, and as an atomic weight of 9⋅2 suited the properties of the metal in the tables of periodicy constructed by MM. Mendeleef and Lothar Meyer, this atomic weight has, up to quite recently, been generally accepted by chemists. As a welcome confirmation to this came a determination of the specific heat of the metal by Professor E. Reynolds, J who found that for its atomic heat to be near the normal number 6⋅0, its atomic weight must be 9⋅2 and not 13⋅8. Almost immediately afterwards a second determination of the specific heat was made by MM. Nilson and Petterson, who, however, obtained a result agreeing not with the lower atomic weight hut with the higher. The reasons for these conflicting opinions are to be found—first, in the anomalous position of glucinum among the elements; secondly, in the difficulties which surround the preparation of even small quantities of the free metal in a tolerably pure condition; and thirdly, in the fact that no volatile compound of glucinum is known of which the vapour density might be easily determined.
Separation and size determination of human serum lipoproteins by agarose gel filtration
