110 



CHEMISTRY. 



and a drop or two of the liquid to be tested should 

 be made to slip slowly down, that the reaction at the 

 point of contact may be carefully noted. 



Cobaltous nitrate may be substituted for the ura- 

 nium salt, and gives an almost equally delicate re- 

 action, but the color of the cobalt salt is an objec- 

 tion. 



Explosiveness of Methyl-Nitrate This sub- 

 stance, the explosion of a sample of which 

 caused the unfortunate death of the promising 

 young chemist, E. T. Chapman, during the past 

 year, may be rendered non-explosive, accord- 

 ing to Girard, by mixing it with other liquids, 

 such as methyl ethyl or amyl alcohol, acetom, 

 benzol, or toluol. One part of methyl-nitrate 

 diluted with two or three parts of either of 

 these liquids, does not explode either on heat- 

 ing its vapor or by a blow. In such solutions, 

 therefore, it is best kept for use. 



Hydrogen in the Metals. It is stated by 

 MM. Troost and Hautefeuille that potassium, 

 sodium, and palladium, combine with hydrogen, 

 while a considerable number of other metals 

 merely dissolve this gas. Iron, nickel, cobalt, 

 and manganese, offer striking analogies in the 

 manner in which they behave with' hydrogen 

 at different temperatures. The facility with 

 which they absorb or give off hydrogen gas 

 depends greatly on their physical condition. 

 An ingot of pure nickel gave out, in a vacuum, 

 at a red heat, one-sixth of its volume of hydro- 

 gen. Laminae of nickel, obtained electrolyti- 

 cally, gave out forty times their volume. Pul- 

 verulent nickel gave out one hundred times its 

 volume, and remained pyrophoric after the 

 escape of the hydrogen. An ingot of cobalt 

 gave out one-tenth of its volume, electrolytic 

 laminae of cobalt thirty-five times their volume, 

 and pyrophoric cobalt powder one hundred 

 times. It also remained pyrophoric after the 

 loss of the hydrogen. Soft iron in ingots gives 

 off one-sixth of its volume, and gray cast-iron 

 more than the half. Electrolytic laminse of 

 iron gave off two hundred and sixty volumes. 

 In fine, it may be said that iron, nickel, and co- 

 balt absorb directly hydrogen gas, but it cannot 

 be said that combination ensues, just as has 

 been already shown in the case of lithium and 

 thallium. 



Maltose. The statement of O'Sullivan that 

 the action of nialt-extract upon starch pro- 

 duces not dextrose, as had been supposed, but 

 a compound sugar having the formula Ci 2 

 HaaOn, and which he named maltose, has been 

 reinvestigated by Schulze, and confirmed. This 

 sugar reduces the copper test less actively than 

 dextrose, but possesses a much greater rotatory 

 power. Schulze's experiments were conducted 

 with diastase precipitated from malt-extract 

 by alcohol. Starch-paste treated with this at 

 a temperature of 60 was rapidly saccharified. 

 After concentration and precipitation of the 

 dextrine by alcohol, the solution was evaporated 

 to a sirup, treated with alcohol, the clear solu- 

 tion poured off and evaporated over sulphuric 

 acid. Crystals first appeared on the walls of 

 the vessel, and finally the whole solidified to a 



crystalline mass. Recrystallized from water or 

 alcohol, maltose contains crystal water, which 

 is readily given up at 100. In appearance 

 maltose resembles dextrose, but is distinguished 

 from it by its composition, its reducing power, 

 and its action on a polarized ray. By boiling 

 with dilute acids it is converted into dextrose. 

 It is, therefore, an intermediate product be- 

 tween dextrine and dextrose. 



New Process for determining the Extraneous 

 Alcohol in Wine. In a paper on this subject, 

 published in Les Hondes, M. Maumene describes 

 a new method for getting at the amount of al- 

 cohol added in the adulteration of wine. He 

 takes the ground that the quantity of glycer- 

 ine and succinic acid in wine, as produced by 

 the fermentation of glucose simultaneously 

 with alcohol, will be proportionate to the lat- 

 ter; the exact knowledge of their amount 

 will therefore serve to indicate the quantity 

 of extraneous alcohol added to the wine. He 

 estimates these substances in the following 

 way: 



To half a litre of wine, concentrated by evapora- 

 tion to 335 c.c., he adds oxide of lead enough to 

 cause every trace of color to disappear. A gray pre- 

 cipitate is formed. Filter, wash the precipitate, and 

 evaporate to dryness in the water-bath. Treat the 

 evaporated residue with absolute alcohol, holding a 

 little hydrated oxide of lead in suspension. Stir, 

 leaving the mixture to stand for some hours, and 

 filter. The liquid thus obtained is colorless. If sub- 

 mitted to a current of carbonic acid it grows turbid, 

 but becomes clear again on filtration. It is dried at 

 110 C., and weighed as pure glycerine. To determine 

 succinic acid, treat a litre of wine with albumen, or 

 raw-hide, insufficient quantity to remove all the tan- 

 nin. Mix with hydrated oxide of lead (after concen- 

 tration^ till the color is entirely removed, and pre- 

 serve the filtrate for the determination of glycerine. 

 The precipitate is kept for a long tune in contact 

 with boiling water, containing about ten per cent, 

 of nitrate of ammonia. The clear liquid, obtained 

 on fresh filtration, contains all the succinic acid in the 

 state of succinate of lead, besides other salts of the 

 same base. It is treated with sulphuric acid, and 

 filtered again, when we have a perfectly colorless 

 liquid containing free succinic acid. After having 

 heated to expel the excess of sulphuric acid, the 

 liquid is concentrated to about 100 c.c., and neutral- 

 ized with ammonia. Heat sufficiently to expel any 

 excess of ammonia, and add a few drops of ferric 

 chloride, which has been previously kept for a long 

 time in contact with sesquioxide of ironj so as to in- 

 sure the absence of free hydrochloric acid. Finally, 

 collect the deposit of succinate of iron which forms, 

 wash it well, ignite, and weigh the residual sesqui- 

 oxide. This weight, x 1.978, gives the quantity of 

 succinic aaid existing in the quantity of wine ana- 

 lyzed. 



Non- Arsenical Green Paints. Owing to the 

 poisonous qualities of arsenical paints many at- 

 tempts have been made to find some suitable 

 substitute that should not only possess equal 

 advantages of color and body, but that might 

 be cheaply manufactured. Several have been 

 produced possessing every desirable quality 

 but cheapness, and this drawback appears now 

 to have been overcome by an Italian chemist 

 named Casali. He states : 



That the existing chrome greens, such as Guignet's 

 green (hydrated sesquioxide of chrome), called also 



