The present inquiry is closely connected with some of the phenomena presented in golf:—especially the fact that a ball can be “jerked” nearly as far as it can be “driven.” For this, in itself, furnishes a complete proof that the duration of the impact is exceedingly short. But it does not appear that any accurate determination of the duration can be made in this way. Measurements, even of a rude kind, are impracticable under the circumstances.

In 1887 I made a number of preliminary experiments with the view of devising a form of apparatus which should trace a permanent record of the circumstances of impact. I found that it was necessary that one of the two impinging bodies should be fixed:—at least if the apparatus were to be at once simple and manageable. This arrangement gives, of course, a result not directly comparable with the behaviour of a golf-ball. For pressure is applied to one side only, both of ball and of club; but when one of two impinging bodies is fixed it is virtually struck simultaneously on both sides.

In former papers on the pharmacological action of Strophanthus, dating from 1869, I selected for description, from the considerable number of experiments that had been made, merely those experiments which sufficed to illustrate the general features of the action, and especially such effects as seemed likely to form a basis for the application of Strophanthus to the treatment of disease.

I had intended to have followed, at no distant date, these preliminary and somewhat fragmentary notices by a more complete description of the pharmacological action, for which, indeed, nearly all the required experimental data had several years ago been obtained; but unavoidable circumstances prevented this intention from being fulfilled. In this part of the present paper the fuller description will be given; and if any excuse were required for doing so, it may perhaps be found in the circumstance that the anticipation of the therapeutic value of Strophanthus has been amply confirmed by the important position now occupied by it as a therapeutic agent.

The following analyses were made some years ago, principally with the object of ascertaining the state of oxidation of the manganese in the nodules. The nodules examined came from three different localities, two of them oceanic and the third littoral. Samples marked I., II., and III. are from nodules brought up in the trawl on board the “Challenger,” on 13th March 1874, in lat. 42° 42′ S., long. 134° 10′ E. The depth of the water was 2600 fathoms, and the temperature of the bottom water 0·2° C. The density of the bottom water was 1·02570 at 15·56° C. Being from a high southern latitude, and therefore near the source of surface aeration, the water is highly charged with atmospheric gases, especially oxygen. It contained, per litre, 18·4 c.c. of mixed nitrogen and oxygen, of which 31·81 per cent, was oxygen, and 27·33 c.c, or 53·7 milligrammes, loosely-bound carbonic acid. The position of the station is about 400 miles south-west of the nearest part of the Australian coast, and about 500 miles west of Tasmania. It was the deepest water observed in the Antarctic voyage between the Cape of Good Hope and Melbourne. The haul was a very abundant one, and a few notes which I made at the time may be interesting:—“The water was found unexpectedly deep, the bottom being red clay, with some Foraminifera.

This paper forms the continuation of a paper already communicated to the Royal Society of Edinburgh, and published in the Transactions (vol. xxxv. pp. 377–390). Strictly speaking, it is third of a series bearing on the same subject. In the first I showed that when a current is passed along a longitudinally magnetised nickel wire a twist is produced similar in character but opposite in direction to the twist which Wiedemann discovered to be produced in iron similarly treated. This was the chief result arrived at; but other results were also obtained, especially with regard to the influence of tension, which called for further investigation. In the later paper, the influence of tension was more thoroughly studied; and also the effect of change of temperature. I also discussed more fully the suggestion first made by Maxwell that the effect discovered by Wiedemann can be explained in terms of the changes of length which Joule observed in iron when magnetised. Obviously the same explanation must be extended to the case of nickel, which Barrett had found also to be subject to changes of length when magnetised. Mr Bidwell's recent elaborate measurements of these changes of length enabled me to make an approximate calculation of the twist in an iron tube longitudinally and circularly magnetised. The comparison of the result as calculated for a tube with the result observed for a wire of the same diameter, established, in my opinion, the sufficiency of Maxwell's explanation.

Noting the direction of the wind is part of the regular routine of observations at the Observatory on the summit of Ben Nevis. Owing to the climatic conditions, especially the frequency of frozen fogs in winter, anemometers are practically useless, but the record is made complete enough for many purposes by the system of hourly observations; at each hour of the day and night the wind, at the time of making the observation, is noted, and the number of entries of each wind direction in the day, month, or year must very nearly represent the relative frequency of such winds for that time. Table I. is a summary giving the number of times each wind is observed in each month of the year on an average of six years (1884–89); February being given in duplicate, that in the body of the table containing 28 days, and that at the foot 29, with the winds divided in the same proportion. The wind is observed to 32 points, but the entries have been reduced to 8 points for this paper by counting all the bys to their adjacent octant, and halving the 8 intermediate points between the octants; thus all N. by E. count as N., all N.E. by N. as N.E., while the N.N.E. entries are halved between N. and N.E., and so on. Perhaps a stricter method of reduction would have been to divide the intermediate points in the ratio of the relative frequency of the adjacent octants, but this would have been considerably more laborious, and of doubtful utility; still it should be borne in mind that the method used tends to smooth out any sudden changes in the frequency of winds of nearly the same direction.

It seems strange that a principle so fundamental and so widely used as Lagrange's Rule for Solving a Linear Differential Equation should hitherto have been almost invariably provided with an inadequate demonstration. I noticed several years ago that the demonstrations in our current English text-books were apparently insufficient; but, as the method by which I treated Linear Partial Differential Equations in my lectures did not involve the use of them, it did not occur to me to analyse them closely with a view to discovering in what the exact nature of the defect consisted. The consideration of certain special cases recently led me to examine the matter more closely, and I was greatly surprised to find that most of the general demonstrations given are vitiated by a very obvious fallacy, and in point of fact do not fit the actual facts disclosed by the examination of particular cases at all.

The worms which form the subject of the present communication were forwarded to me, in a living condition, from Kew Gardens.

I have received lately a considerable number of living Oligochæta from those Gardens, through the kindness of Mr Dyer, who permitted me to have the earth arriving from different parts of the world in the Wardian cases, in which plants are packed for travelling, thoroughly sifted, with a view to preserving the worms which had been accidentally included. By these means I have succeeded in obtaining some very interesting new forms, as well as a number of others which are still imperfectly known. The species which I describe in the present paper appears to be a new species of Eisen's genus Ocnerodrilus. The genus Ocnerodrilus was formed by Eisen in 1878 [1] for a small worm found in Fresno County, California. The specimens were all met with in “an irrigation box,” where they were found crawling among the algæ which covered the boards. It is evidently, therefore, aquatic in its habits, but Eisen contrasts its slow movements with the rapid swimming of Lumbriculus and Rhynchelmis, comparing it in general appearance with a small species of Lumbricus.