It is here intended to show how a storm with a diameter of several hundred miles, and with a comparatively low vertical height, can move and only in contact with the resisting surface of the ground, but not on a frictionless surface. Exceptional cases are all here received owing to the complexity of the subject, and also to the comparatively few conclusions which have been arrived at in the millions of observations which have taken place. Let this storm be supposed to be inaugurated in the United States, and be described as being a vast mass of rarefied air enclosed within its surrounding isobarics. In this form, as is well known, it does not cross the Atlantic and to the British Isles; it only alters its position in the form of a circular-atmospheric wave, and by the “Curve of Outward Propagation” in front, described in the paper of 1877–78, page 574, and which is accepted by a well-known continental meteorologist. As shown by the Eev. W. Clement Ley, cirrus clouds aloft move in front and from low to high pressure. This also takes place with the Curve, which, by the alteration of the position of the atmosphere aloft, may thus probably produce these clouds. Opening out of a storm in this way in front, of course fills up in the rear.

This form, which in many respects is a most interesting intermediate type, was dredged at Station 212, south of the Philippine Islands, on the 30th January 1875, in lat. 6° 55′ N., long. 122° 51′ E., at a depth of 10–20 fathoms, on a sandy bottom. The total length is about 52 mm., with a variable diameter of about 2 mm. at the blackish anterior region, and 4 or 5 mm. at the posterior. The tentacular or branchial region has a length of 6 or 7 mm.

By the help of an iron-copper junction introduced into the smaller compression apparatus lately described to the Society, I have examined for a number of substances the rise of temperature produced by a sudden application of great pressure, and the corresponding fall of temperature when the pressure was very suddenly relaxed. The copper-iron circuit is, however, too little sensitive for very accurate measurements ; as, from the nature of the apparatus, the wires must be so thin as to have considerable resistance, and the thermoelectric power of the combination is not large.

The object of the present communication is to briefly consider the general and minute structure of the corallum of the recent Tubipora musica, with special reference to the association of the genus Tubipora with the extinct genus Syringopora, as advocated by many modern naturalists. The method of inquiry that I have pursued in carrying out this investigation has been principally that of preparing similar thin and transparent sections of both the recent and the extinct types; and though there are special difficulties in the way of any examination of Tubipora by this method, I have been able to overcome these in a satisfactory manner, and to prepare a number of thin sections which answer all the requirements of the case.

This is a one fluid battery. The two plates are zinc and carbon. The solution is a solution of iodide of potassium in water, in which iodine is dissolved. The usual strength I use is 1 oz. of iodide of potassium in 2 oz. of water. In this dissolve ½ oz. of iodine, but the strength of the iodine and of the iodide of potassium can be considerably varied without affecting the electromotive force.

The iodine is meant to prevent polarization by uniting with the nascent hydrogen to form hydriodic acid, which will then unite with the caustic potash, to form iodide of potassium and water. In this way the iodide of potassium acts as a carrier of iodine, from the iodine in solution, to the zinc plate.

The theory of “Valency” or “Atomicity,” while explaining satisfactorily many chemical phenomena, still leaves unexplained many facts, such, for instance, as the varying atomicities of several elements, the composition of double salts, water of crystallisation, &c. This arises from assuming that chemical affinity acts in an atomic indivisible manner, which is not warranted by the facts. If we take, for instance, nitrogen in the compound, NH3 and NH4Cl, it acts in the one case as a triad, while in the other it is said to be a pentad. Now, ïn the case of the NH4Cl in this view, we have the chlorine represented as directing all its affinity to the nitrogen, for which it usually has such a feeble affinity, while it has no action on the hydrogen, for which its affinity is usually so intense. Now, if we get rid of the idea of the atomic action of affinity, we may represent the chlorine dividing its action among all the four atoms of hydrogen, giving on the average ¼ to each; and the nitrogen, in the same manner, giving ¾ to each; and thus, the whole molecule is bound together.

The family Molgulidœ was established by Lacaze-Duthiers in 1877, and distinguished from the Cynthiadœ, with which it had formerly been united by Heller.

Lacaze-Duthiers divides the species known to him into four genera,—Anurella, Molgula, Ctenicella, and Eugyra,—of which Anurella forms a sub-family or section the Molgulidœ anurœ, the other three constituting the Molgulidœ urodelœ. The character by which Anurella is distinguished from the other genera is the tail-less amoeboid larva; but this most interesting developmental difference does not seem to be accompanied by any structural features in the adult animal, and consequently it becomes impossible to distinguish the genus unless one examines the animal alive and at the breeding season.

In continuation of a short paper on meconic acid previously communicated to the Society, I submit the following notice of some of the salts of comenic acid.

As is well known, comenic acid is formed from meconic acid by elimination of carbonic anhydride, according to the equation -C7H4O7=C6H4O5+CO2. This change may be effected by heat alone, but a better product is obtained by the action of boiling aqueous hydrochloric acid. It was by the latter method that the acid used in my experiments was prepared. Comenic acid is easily purified by crystallisation from boiling water, in which it is sparingly soluble, and by conversion into ammonium salt, which is likewise purified by recrystallisation. Comenate of ammonia forms long well-defined prisms, which are much less soluble in water than the corresponding salt of meconic acid.

The dielectric strength of colza oil (specific gravity ·91) was found to be 2·7, that of air at the ordinary pressure being unity- The rest of the paper is taken up with a description of the phenomena accompanying under different conditions the spark discharge through the oil.