and yet it is a stannous compound, and gives a black precipitate with H_{2}S; so that valency does not necessarily go with the series. The second point is that an objection may be urged, as, for example, in ammonium chloride (the lecturer stated above that here N was a pentad, the addition of the chlorine having caused the N to assume the pentadic character), it may be said, why should you not suppose that it is the chlorine "which has altered its valency, and that the compound should be written: {H {H N { \ {H--Cl {H/ There is something to be said for this view, but on the whole the balance of the evidence is in favor of nitrogen being a pentad. In conclusion the lecturer stated that his principal object was to direct the attention of chemists, and especially of young chemists, to the question: Is there or is there not any evidence derived from the properties, the decompositions, or the relative stabilities of substances to warrant us in believing that two classes of compounds exist: one class in which there is interatomic connection alone, and another in which the connection is molecular? * * * * * FRENCH TOILET ARTICLES. Mr. Martenson, of St. Petersburg, who, it will be remembered, was one of the Russian delegates to the International Pharmaceutical Congress, has been analyzing a number of French preparations for the toilet, most of which are familiar to our readers, at any rate by name and repute. 1. _Eau de Fleurs de Lys_--(Planchon and Riet, Paris.)--An infallible banisher of freckles, etc., etc. The bottle contains 100 grammes of a milky fluid, made up of 97 per cent. of water, 2.5 per cent. of precipitated calomel, and a small quantity of common salt and corrosive sublimate, and scented with orange flower water. 2. _Eau de Blanc de Perles_.--The bottle contains 120 grammes of a weak alkaline solution, with a thick deposit of 15 per cent. of carbonate of lead, and scented with otto of roses and geranium. 3. _Nouveau Blanc de Perle, Extra Fin_.--(Lubin, Paris.)--The bottles contains 35 grammes of a liquid consisting of water, holding in suspension about equal parts of zinc oxide, magnesic carbonate, and powdered talc, perfumed with otto of roses. 4. _Lait de Perles_.--A close imitation of No. 3, the bottle holding nearly three times the quantity for the same price. The amount of the precipitate in this case is 20 per cent. 5. _Lait de Perles_.--(Legrand, Paris).--The bottles contain 65 grammes of a thick white fluid, the precipitate from which consists of zinc oxide and bismuth oxychloride, and is scented with rose water.