while on the floors of the spots, here and there, were similar single cloudmasses, the distribution of which varied from time to time, the spectrum of these masses resembling that of their fellows on the general surface of the sun.

I have before stated that the region of a spot comprised by the penumbra appears to be shallower in the spots I have observed lately (we are now near the maximum period of sun spots); I have further to remark that I have evidence that the chromosphere is also shallower than it was in 1868.

I am now making special observations on these two points, as I consider that many important conclusions may be drawn from them.

Mr. Holiday's drawings and remarks.

DESCRIPTION OF PLATE III.

1. Prominence much bent.

2. Prominence encroaching over limb-bright line crossing black line.

3. Black line (F) curved downwards, sometimes nearly touching iron line below.

4.

5. Prominence nearly divided.

6. Intensely brilliant flashes above and below centres (of F lines); the interruptions very complete.

7 & 8. Curves in prominence very marked.

9, 10, 12, 14, 15. My own drawings, made during first and second outbursts. 11. A lozenge on the limb as seen with a tangential slit.

13. A lozenge as seen on the sun itself.

VII. "On some Elementary Principles in Animal Mechanics.-— No. IV. On the difference between a Hand and a Foot, as shown by their Flexor tendons." By the Rev. SAMUEL HAUGHTON, F.R.S., M.D. Dubl., D.C.L. Oxon., Fellow of Trinity College, Dublin. Received April 23, 1870.

The fore feet of vertebrate animals are often used merely as organs of locomotion, like the hind feet; and in the higher mammals they are more or less "cephalized," or appropriated as hands to the use of the brain.

The proper use of a hand when thus specialized in its action, is to grasp objects; while the proper use of a foot is to propel the animal forward by the intervention of the ground.

In the case of the hand, the flexor muscles of the fore arm act upon the finger tendons, in a direction from the muscles towards the tendons, which latter undergo friction at the wrist and other joints of the hand, the force being applied by the muscles to the tendon above the wrist, and the resistance being applied at the extremities of the tendons below the wrist by the object grasped by the hand.

From the principle of "Least Action in Nature' we are entitled to assume the strength of each portion of a tendon to be proportional to the force it is required to transmit; and since, in a proper hand, these forces are continually diminished by friction, as we proceed from the muscle to

the fingers, we should expect the strength of the tendon above the wrist to be greater than the united strengths of all the finger-tendons.

Conversely, in a proper foot, the force is applied by the ground to the extremities of the tendons of the toes, and transmitted to the flexor muscles of the leg, by means of the tendons of the inner ankle, which undergo friction in passing round that and the other joints of the foot. In this case, therefore, we should expect the united strengths of the flexor tendons of the toes to exceed the strength of the flexor tendons above the heel.

In the case of the hand, friction acts against the muscles; in the case of the foot, friction aids the muscles.

I have measured the relative strengths of the deep flexor tendons of the hand above and below the wrist in several animals, and also the relative strengths of the long flexor tendons of the foot above and below the ankle in the following manner :—

I weighed certain lengths of the tendons above the wrist and ankle, and compared these weights with the weights of equal lengths of the flexor tendons of the fingers or toes, assuming that the weights of equal lengths are proportional to their cross sections, and these again proportional to the strengths of the tendons at the place of section. The difference between the weights above and below the joint represents the sum of all the frictions experienced by the tendons between the two points of section. The following Tables contain the results of my measurements :—

TABLE I. Friction of Long Flexor Tendons of Toes. (Cross section of toe tendons greater than cross section of muscle tendons.)

The foregoing animals all realize the typical idea of a true foot, with a variable amount of friction at the ankle-joint; this friction disappearing altogether in the Boomer Kangaroo, whose method of progression realizes absolute mechanical perfection, as no force whatever is consumed by the friction of the flexor tendons at the heel.

The only animals whose feet deviated from the typical foot were three, viz. Alligator, Common Porcupine, and Phalanger. In these animals the foot has the mechanical action of a hand, or grasping organ; and the flexor tendons above the ankle exceeded those below the ankle by the following amounts:-

1. Alligator

2. Common Porcupine..

3. Phalanger

per cent.

11.5

20.0

29.2

In the case of the flexor tendons of the hand, I obtained the following results:

TABLE II. Friction of Deep Flexor Tendons of Hand. (Cross section of muscle tendons greater than cross section of finger tendons.)

It will be observed that the fore foot of the Goat, regarded simply as an orrgan of locomotion, attains a perfection comparable with that of the hind foot of the Kangaroo, no force being lost by friction at the wristjoint.

The only animal in which I found a departure from the typical hand was the Llama, in which the flexor tendons of the fingers exceed the flexor tendon above the wrist by 14.4 per cent.

The bearing of the foregoing results on the habits of locomotion of the several animals will suggest themselves at once to naturalists who have carefully studied those habits. I shall merely add that the subject admits of being carried into the details of the separate or combined actions of the several fingers and toes, and that the habits of various kinds of monkeys in the use of certain combinations of fingers or toes may be explained satisfactorily by the minute study of the arrangement and several strengths of the various flexor tendons distributed to the fingers or toes.

VIII. "Experiments on the effect of Alcohol (Ethyl Alcohol) on the Human Body." By E. A. PARKES, M.D., F.R.S., Professor of Hygiene in the Army Medical School, and Count CYPRIAN WOLLOWICZ, M.D., Assistant Surgeon, Army Medical Staff. Received April 4, 1870.

As a knowledge of the physiological effects of alcohol on the human body is a matter of great importance, and as previous observations leave some points in doubt, we took the opportunity which the willingness and zeal of a very intelligent healthy soldier afforded us of investigating this subject.

In order not to lengthen the paper, we have given only our own observations, without referring to those of others.

The plan of observation was as follows:-For twenty-six days the man remained on a diet precisely similar as to food and times of meals in every respect, except that for the first eight days he took only water (in the shape of coffee, tea, and simple water); for the next six days he added to this diet rectified spirit, in such proportion that he took, in divided quantities, on the first day one fluid ounce (=28.4 cub. centims.) of absolute alcohol; on the second day two fluid ounces; on the third day four ounces, and on the fifth and sixth days eight ounces on each day. He then returned to water for six days, and then for three days took on each day half a bottle (=12 ounces, or 341 c. c.) of fine brandy, containing 48 per cent. of alcohol. Then for three days more he returned to water.

There were thus five periods, viz. of water-drinking, alcohol, water, brandy, water.

Before commencing the experiments, the man, who had been accustomed to take one or two pints of beer daily, abstained altogether from any alcoholic liquid for ten days.

This man, F. B., is twenty-eight years of age, 5 feet 6 inches in height, and his usual weight is 134 or 136 lbs. He is finely formed, with little fat, and with largely developed powerful muscles; he has a clean smooth skin, a clear bright eye, good teeth, and is in all respects in perfect health. He is very intelligent, and assisted us so much that we are quite certain that there has not been a mistake even for a minute in the time of taking the temperatures and passing the urine. As he had always been accustomed to smoke, we thought it proper to allow him half an ounce of tobacco daily, for fear the deprivation of it might disturb his health.

In addition to the experiments recorded in this paper, we tested the accuracy of his vision, and the muscular power before and during the use of alcohol; but as we could not detect any difference, we do not give the experiments.

Our object being to test the dietetic effects of alcohol, we gave it in small and large quantities, but avoided producing any extreme symptoms of narcotism.

FOOD.

Amount of solid food taken daily through the whole period :—

The meat was fried in the fat.

The meals were taken always at the same time, viz. at 8 A.M., 1.30 P.M., and 5 P.M.; at 10 P.M. he took four ounces of water.

It was not intended that the quantity of water should be altered; but through a misconception, the man thought the spirit and brandy were to take the place of the water, and took therefore less water in proportion. In one respect the mistake was fortunate. The total amount of water taken in the so-called solid food, and as drink, was about 72 fluid ounces, or 2059 c. c. daily during the water days, and a little less during the days on which he took alcohol and brandy.

* The nitrogen in the beefsteak was determined once; the result was almost identical with the results given in experiments in exercise recorded in No. 94 (1867) of the Proceedings of the Royal Society. As the bread was analyzed on a former occasion, it was not so now; its composition is very constant, the same amount of flour, water, and yeast being always used in the hospital bakery at Netley.