LIQUID PHOSPHORUS.
303
affected by hot or cold nitric acid, and metals plated on it could be readily dissolved off without injuring the electrode ; but as the best aluminum on the market is not quite pure, there is a possibility in time of a slight loss in weight. Even with this drawback, however, aluminum cathodes will be serviceable for ordinary commercial analysis, especially copper analysis, in which I think they would find their greatest field of usefulness. It has been suggested to me that aluminum, heavily plated with platinum, might be made to serve as an anode ; but of this I am somewhat doubtful, as I have not yet had opportunity to try it. This substitution of aluminum for platinum I make simply as a suggestion, for my experiments have not been numerous enough or minute enough to announce it as a scientific improvement, except in the case of copper analysis. But should it prove to be sufficiently adapted to the purpose which I have designated, it has two great advantages : first, as compared with platinum it is very much lighter, and its use would reduce the liability to error in the weight of the deposited metal, which is small as compared with the weight of the electrode ; second, it is vastly cheaper than platinum, costing only one-sixtieth as much in the manufactured condition.
NOTE ON LIQUID PHOSPHORUS. By F. P. VENABLE AND A . W.BELDEN. Recewed February r4* i898.
1
N 1875 Hourton and Thompson’ reported the formation of a peculiar modification of phosphorus formed on boiling ordinary phosphorus for five minutes with a strong solution of potash. T h e alkaline solution was poured off and the liquid phosphorus washed. It is said to remain liquid for months and solidifies only on cooling to 4-3.3’. It is further reported as not oxidizing in the air nor giving off light in the dark. On becoming solid it forms ordinary wax-like phosphorus and a second variety of crystalline phosphorus. These singular statements are cited in Dammer’s I ‘ Handbuch der anorganischen Chemie” and the chemical literature available to us has been searched in vain for any further mention of this 1
Avch. d . Pharm., (3), 6, 49.
304
H. W. YILEY AND 11'.
D. BIGELOW.
strange variety of phosphorus. It has therefore seemed advisable to give a brief notice of some experiments in which it was attempted to form this liquid phosphorus. Five grams of fresh wax phosphorus were placed in a flask with 80 cc. of a saturated solution of potassium hydroxide and boiled for five minutes in a neutral atmosphere (nitrogen was used). This was washed with water at 19' and on the second washing the phosphorus solidified. If the alkaline solution was poured off directly, the phosphorus caught fire, hence it was usually poured off to small bulk, diluted with water, and again poured off and so on until the phosphorus was washed. In every experiment performed the phosphorus solidified after the second or third washing. T h e amount of phosphorus, the time of boiling (three, five, ten, and fifteen minutes), and the strength of the potassium hydroxide solution (saturated to ten per cent. solution), were each varied without securing the liquid phosphorus. I t is, however, true that the phosphorus becomes liquid on heating under the alkaline solution and, if left covered with the same, stays liquid a long time, solidifying only when strongly cooled. It seems to give off occasional bubbles of gas during this standing and is probably being slo~vlychanged into phosphine at ordinary temperatures. W e are quite at a loss to know how the authors mentioned above secured their liquid phosphorus and how it could prove unalterable in the air. I n all of our experiments it was peculiarly inflammable. USIVERSITY O F S O R T H CAROLIXA
[CONTRIBUTIOXS
FROM THE CHEMICAL
STATES
LABORATORY O F THE
DEPARTMENT O F AGRICULTURE, NO.
UNITED
32.1
CALORIES OF COI'lBUSTION IN OXYGEN OF CEREALS AND CEREAL PRODUCTS, CALCULATED FROfi ANALYTICAL DATA.' BY H . W WILEYASD W. D. BIGELOR. Recei%edMarch
10.
1898
PRISCIPLES IXVOLVED.
T
HE calculation of the heat of combustion of food products is
tions.
now quite generally practiced in analytical determinaT h e development of the methods of burning in com-
1 Read before the American Chemical Society and Section C of the American Association for the Advancement of Science, a t Detroit, August 12, 1897.
