Blue Liquid Research Articles

Dissociation pressures of alcoholates of cobalt isothiocyanate

The systems Co(NCS)2 – methanol vapor and Co(NCS)2 – ethanol vapor have been studied. The known dialcoholates and also two previously unreported tetraalcoholates, were prepared. The dissociation pressures of the alcoholates were measured at several temperatures. Values of ΔH0 and ΔS0 at 25 °C were calculated for the reaction Co(NCS)2 + nROH = Co(ROH)n(NCS)2, with n = 2 and 4. Monoalcoholates were not found. A metastable system dialcoholate plus viscous blue liquid is discussed.

A yellow glass filter for colour-temperature measurements

A glass filter is described which enables the colour temperature of lamps to be measured, using standard lamps which operate at lower colour-temperatures. The filter is yellow in colour and made from Corning 346 and 507 glasses. The method of construction is described. Colour-temperature measurements made with the glass filter agree to 4°k. with those using the blue liquid filter previously used at the laboratory. The advantages of the yellow filter over the blue filter are that the yellow filter is more stable, the colour-matching properties are better, the energy match is better for a colour match, the temperature coefficient is a fifth of that of the blue filter, and the yellow filter is placed in front of the brighter lamp, so that, for a colour match, the lamps are nearly equidistant from the photometer. The properties of glass filters made from (a) a yellow glass with Zeiss U.G.3, (b) Corning 346 with Chance O.V.2, and (c) Cobalt blue glass are mentioned.

On the Colour of Sea Water

AITKEN (Proc. R. S. E., vol. ii. p. 472, 1882) has given a complete theory of the colour of sea water as observed at various places, based upon the principle that sea water is a blue liquid. According to this view, the green tint often observed in sea water, especially near land, is to be explained by the presence of fine yellow particles. During a recent voyage by the Messageries steamer Polynesien, I was permitted, through the kindness of Commandant Bullard, to erect a tube 736 cm. long against the rail of the after-deck, and to pass through it a continuous stream of water from the ship's salt water service. The water was taken in well forward and at a depth of two or three metres, and consequently was not soiled by the passage of the ship. I made a series of observations with the apparatus described, matching the colour of the sea water by making mixtures of definite substances, and using these mixtures to fill a tube 18 cm. long, placed alongside the water tube. Both tubes were illuminated by diffused daylight reflected from a white screen, and by the aid of diaphragms, c but, owing to the uncertainty arising from the contamination of the water by the varnish with which the interior of the tube was protected, it is useless to comment on most of the results obtained, except in so far as they give a means of easily reproducing the exact tint of pure sea water as seen through a column 736 cm. long. Make up the following solution:—

The Colour of Sea Water

AS Mr. Threlfall, in his letter to NATURE of March 16, seems to have fallen into an error regarding the explanation of the colour of sea water, given by me in the paper referred to in his letter, perhaps I may be allowed to make a few remarks on the subject, He says my explanation is based on the principle that sea water is a blue liquid, and that the green tint often seen in sea water is due to the presence of yellow particles. Now, while it is pointed out in the paper referred to that yellow particles will make a blue water appear greenish, yet it is nowhere stated that yellow particles are the exclusive cause of greenness in sea waters. What may have caused Mr. Threlfall to make this overlook, may be the fact that only an abstract of the paper was published, and the different points, therefore, not fully explained. Still, I think there is enough in the abstract to show that greenness in sea water was recognised to be due in some cases to other causes than the one referred to in Mr. Threlfall's letter.

IX. On the chemical action of atmospheric electricity

The intimate connection existing between the chemical constitution of various substances and their condition in regard to electricity, has now been long known. So true is this, that the very order of their affinities has also, for a considerable period, been acknowledged as greatly within the control of this agent. With this object in view, the electrical influence, as exhibited in the ordinary way, as well as by the Voltaic battery, has successively confirmed its results in the experiments of Nicholson, Cavendish, Sir H. Davy, Children, and the French chemists. This being the case, it is not my purpose to advert to any new source of electrical accumulation, but to describe what appears to me as the link connecting the researches of Dr. Franklin with the electro-chemical theory of Sir H. Davy. With this view, in August 1824, I elevated the kite in an atmosphere favourable to the exhibition of its phenomena. It was raised from an apparatus firmly fixed in the earth, and was insulated by a glass pillar. The usual shocks were felt on touching the string, which simple fact I am induced to mention from the circumstance of no electrometer having been employed. The portion of string let out with a double gilt thread passed through it, was about five hundred yards. I then made the connection shown in the accompanying sketch, where the straight glass tubes A B, having platina wires passed from above half way down their axes, and standing in their respective glass cups C D, were filled with a solution of sulphate of soda coloured with syrup of violets, connected also with each other by the bent glass tube E, likewise filled with the above solution in the usual manner. A portion of gilt thread d was then brought from the tube at A and united to the kite-string K, whilst a similar thread b was carried from B to the earth. Bubbles of hydrogen in A and of oxygen in B, soon appeared. In about ten minutes, the blue liquid in A became green from the separation of the soda, whilst the sulphuric acid, by passing to the pole in the tube B, changed its contents, as usual, red. The experiment was then discontinued. In having the honour to communicate the result to the Royal Society, I must remark, that it was my intention to have pursued this simple application of electricity, in the expectation of arriving at more extended and important conclusions, which, however, numerous circumstances have hitherto prevented me from accomplishing.