until all the iodine is precipitated as iodide of lead, which is then separated by filtration and treated for the production of iodine or iodides. After filtration the liquid is boiled, nitrate of soda is added to convert the chloride of potassium present into nitrate of potash. The latter is separated by crystallisation. There remains a solution of common salt containing traces of ammonia from the previous soda operation and a trace of chloride of potassium. This solution is again treated by the ordinary ammonia-soda process for the production of bicarbonate of soda and white alkali.

Under the title of "Country Laboratory Apparatus," Mr. Edward T. Hardman, F.C.S., of H.M. Geological Survey, Ireland, describes a substitute for crucible jackets, useful to those who have occasion to shift their quarters often, and are obliged to work with a necessarily limited laboratory accommodation. The ordinary crucible jacket being made of sheet-iron has in reality but one use-to protect the flame from currents of air. An ordinary earthenware flower-pot answers the purpose in every respect. It is the proper shape,

and being made of a non-conducting material it in a great measure prevents loss of heat from the burner. The bottom of the flower-pot has a circular hole this serves for the introduction of the Bunsen burner. As the supply of air would be otherwise insufficient, it will be necessary to enlarge the opening. This can be easily done by cutting the aperture nearly in the form of a cross, and not too large. A current of air is then obtained which not only steadies the flame, but acts in some degree as a blast. The flower-pot may be supported in the ring of a retort-stand in the usual way. The chimney is a second flower-pot inverted. To support it the handiest way will be to make three S hooks of stout wire, and having passed the narrow end of the pot upward through the ring, fix the rim within the hooks caught on the ring, as in Fig. 1. The apparatus acts admirably as a small gas furnace for crucible operations, such as the fusion of silicates with carbonate of soda—as in the analyses of rocks; while for simple ignition of precipitates it renders the flame of a common glass spirit-lamp most effective. The size of the flower-pot required will, of course, depend on that of the crucible and of the burner used. The support for the crucible may be either a triangle of wire covered with

pipe-shank, the end of the wire being bent upwards and formed into hooks so as to hang on the edge of the flower-pot (Fig. 3), or three pipe-covered wires, suspended in the position of the ribs of a crucible jacket. The former is necessary for small crucibles. The flower-pot also makes an excellent lampscreen, for steadying and concentrating the flame under evaporating basins, &c. A small flower-pot with wire gauze tied over the top is a very effective low temperature lamp when the gas is lighted before the gauze. If the gas is lighted above the gauze an argand lamp giving a large clear blue flame is obtained. In the latter case a common burner can be used. Having occasion to determine the volatile matter of a coal, and not having at hand the usual elaborate arrangements, Mr. Hardman thought of the schoolboy's method of manufacturing coal-gas. The retort he uses is a common clay tobacco-pipe. A piece of coal is put in, the top is luted with clay, and the pipe is inserted in the fire-grate with the stem projecting. Presently a dense smoke issues from it, and and a match being applied a veritable gas light-but not " 16-candle " -results. On opening the luting a piece of coke is found in the pipe. It is obvious that it is only necessary to weigh the pipe and contents before and after the operation, and we have the volatile matter and coke determined. The larger the pipe the better. The coal must be broken small, but not powdered. The pipe is weighed, then filled with the coal aud weighed again to obtain weight of coal. Then inside the top is fitted a circular piece of writingpaper, the use of which is to prevent any of the luting getting down anong the coal, where it could not be removed, and would falsity the last weighing. The top is luted with moist fireclay, or with the cement used for luting the covers of gas retorts, and the pipe being placed in a common coal fire or in a gas furnace from ten to twenty minutes completes the operation. When cool the luting is carefully taken off and the charred paper removed. The pipe and contents being then weighed, the loss gives the volatile matter, the same weighing, of course, determining the coke. If a very exact determination is required, a quantity of the coal may be broken small, well mixed together, and four pipes filled as above. They can all be ignited together in a fire, and weighed very quickly. The results will be found to agree very closely. This tobacco-pipe process has the great advantage of being very expeditiously performed the whole experiment including weighings not occupying more than thirty minutes-and with very simple apparatus.

I. Physical Changes upon the Surface of the Moon.

II. Evolution by Expansion versus Evolution by Natural Selection.

III. The Port of Ymuiden.

IV. Animal Geography.

V. On the Loess of the Rhine and the Danube.

VI. Physiology and its Chemistry at Home and Abroad.

NOTICES OF SCIENTIFIC WORKS.

Mansfield's "Aerial Navigation."

"A Classified English Vocabulary, being an attempt to facilitate a Knowledge of Words and their Meanings by an Arrangement of Ideas according to their Scientific Connection."

Denman's "Wine and its Counterfeits."

Burmeister's" Description Physique de la Republique Argentine." "The Empire of Brazil at the Universal Exhibition of 1876 in Philadelphia."

Greenwood's "Rain and Rivers, or Hutton and Playfair against Lyell and All Comers."

Beard's "Hay-Fever or Summer Catarrh; its Nature and Treatment."
Lochner's "The Solution of the Most Important hitherto Unsolved
Problems in Nature."

Hagen's" Statistical Investigations on Mental Diseases,"
Wyman's "Peabody Academy of Science."

Potts's "Elementary Arithmetic, with Brief Notices of its History."
"Monthly Notices of the Papers and Proceedings of the Royal Society
of Tasmania, for 1874."

Coues's "Abstract of Results of a Study of the Genera Geomys and Thomomys, with Addenda on the Osteology of the Geomyidæ and on the Habits of Geomys Tuza."

Packard's "United States Geological Survey of the Territories." Proctor's "The Sun-Ruler, Force, Light, and Life of the Planetary System."

Tyndall's "Lessons in Electricity at the Royal Institution, 1875-76." Pickering's "Elements of Physical Manipulation."

(Including the Proceedings of Learned Societies at Home and Abroad, and

Notices of Recent Scientific Literature).