This paper was illustrated by two large charts of the world showing, by ISOHYETAL LINES, the rainfall over the different continents in January and July; two large charts showing the months of least and greatest rainfall in Europe, north Africa, and west Asia; and by six sets of smaller charts of thirteen each, showing, by isohyetal lines, the monthly and annual rainfall of Europe, Asia, Australasia, North America, Africa, and parts of South America. The data laid down on these eighty-two charts were taken from a Table comprising about 2000 good averages of rainfall, calculated or collected by the author.

The author gives the results derived from different discussions of nearly eighty thousand observations, made hourly during the eleven years 1854 to 1864. They are as follows:—

1. That the lunar diurnal variation consists of a double maximum and minimum in each month of the year.

2. That in December and January the maxima occur near the times of the moon's upper and lower passages of the meridian; while in June and July they occur six hours later, the minima then occurring near the times of the two passages.

3. The change of the law for December and January to that for June and July does not happen, as in the case of the solar diurnal variations, by leaps in the course of a month (those of March and October), but more or less gradually for the different maxima and minima.

Lord Neaves read a paper entitled “Some Helps to the Study of Scoto-Celtic Philology,” in which, after noticing the mistaken tendencies of the Celtic scholars of former times, both Irish and Scotch, as to the origin and affinities of Gaelic, and adverting to the fact now firmly fixed that it was an Aryan or Indo-Germanic tongue, he submitted a statement of some of the imitations or disguises which words underwent or assumed in passing into Gaelic. Thus it was a peculiarity of Gaelic to avoid the letter p, which it did in various ways. Sometimes it dropped that letter, as when it changed the Latin Pater into Athir, the Latin piscis into iasg, plenus into lán, &c. Sometimes it changed the p into a gutteral c, g, or ch, as seachd for septem, feasgar for vesper.

The author expressed his concurrence with those anatomists who hold that the two tusks of the narwhal are situated in sockets in the superior maxillary bones, and not, as was stated by the Cuviers, in the premaxillæ, or partly in the pre- and partly in the superior maxillæ. He then proceeded to relate some further observations on the dentition of the narwhal, and pointed out, both in the skull of a young male and in those of three well grown fœtuses, an elongated canal on each side of the upper jaw, parallel and inferior to the tusk socket, which had the appearance of a socket for a supplementary tooth, although none protruded from it. In the young male a minute denticle was seen at the bottom of this socket.

This paper contained a brief historical sketch of Ziphius cavirostris. The skull of a specimen caught at sea in 1870, off Hamna Voe, Northmaven, Shetland, was then described, and this skull was compared with previously recorded specimens. A brief historical sketch of Sowerby's whale was then given, a skull in the Edinburgh Museum of Science and Art was described, and reasons were advanced for associating it with the genus Mesoplodon rather than with Ziphius.

The author gave a brief sketch of the various theories which have been advanced by Velpeau, R. Lee, Braxton Hicks, the Hunters, Owen, Weber, J. Reid, J. Goodsir, Virchow, Kölliker, Van Der Kolk, Arthur Farre, and Ercolani regarding to the relations of the maternal blood-vessels to the placenta and chorionic villi. He then proceeded to state the results of his own observations on various specimens of placentæ, some of which had been separated at the full time, others prematurely, and on three specimens attached to the uterine wall.

I have reported already to the Society (p. 688) the results of the cultivation of the Ipecacuan plant in the Botanic Garden, and its successful propagation by Mr M'Nab by root-cutting. By this means it has been sent in considerable quantity to Calcutta, under the direction of the Secretary of State for India. From the Garden at Kew, in 1863, a plant was sent out to Dr King, and of late he has been successful in propagating it by cuttings of the stem above ground. So that from both sources there seems to be every prospect of the plant being extensively cultivated in India, the climate of which in many places is favourable for its growth. The so-called root of the Ipecacuan may be said to be composed of a sort of underground stem capable of producing leaf-buds, as well as true roots.

Seven species belonging to the Echinoderm order CRINOIDEA, were procured during the “Porcupine” dredging expeditions of 1869 and 70. Four of these belong to the free section of the order, and are referred to the genus Antedon.

Having lately obtained from Messrs Johnson & Matthey some wires of platinum, and of alloys of platinum and iridium, I formed them into circuits with iron wire of commerce; and noticed that with all, excepting what is called “soft” platinum, there is more than one neutral point situated below the temperature of low white heat, and that at higher temperatures other neutral points occur. This observation is, in itself, highly interesting; but my first impression was one of disappointment, as I imagined it depended on some peculiarity of the platinum metals, which I had hoped would furnish me with the means of accurately measuring high temperatures (by a process described in previous notes of this series). As this hope may possibly not be realised, I can as yet make only rough approximations to an estimation of the temperatures of these neutral points.

While making some magnetic experiments lately with Mr Fox Talbot, I happened to notice that two equal rectangular pieces of tin plate, when standing nearly parallel to one another on the pole of a large electromagnet, acted on one another so that a vibration communicated to either was in a few seconds handed over to the other, and vice versâ.

The definiteness of the result led me to try the experiment with ordinary bar magnets. Taking two large magnetised bars of almost exactly equal mass, I suspended them with their axes in the same horizontal line, so that their (small) vibrations were executed in that line, their undisturbed periods being very nearly equal, and the distance between them (when at rest) so small compared with their lengths, that we need consider only the magnetic action of the two poles nearest together.

Commencing afresh with the fundamental integral

put

and we have

from which at once

At the suggestion of Professor Tait, I undertook the investigation of the momentary thermo-electric current developed when two conductors or wires of the same metal are brought into contact, the one being at a different temperature from the other.

Platinum was chosen as the most suitable metal to experiment with, in the first instance, as it is free from the interfering action of oxidation at high temperatures.

In the communications made by Sir Robert Christison to the Society in December and April last on the deep-water temperature of Loch Lomond, from observations made by him with a Miller-Casilla thermometer, these important facts were stated:—

(1.) On 12th October 1871, the temperature at the surface was 52·°0, from which it fell, on descending, till at 300 feet below the surface it stood at 42°·0, and this temperature of 42°·0 was uniformly maintained at greater depths or to 518 feet, the depth of the loch at the place of observation.