found his account of the early improvements made in the microscope in 1828 by Tully, and afterwards by Ross, Powell and Lealand, Smith, and Beck; also on the methods of mounting objects by the use of Canada balsam.

Indeed, so many eminent men came at this time to his house in order to examine their specimens by his instrument, that he was compelled to fix one night in the week for their reception, and thus originated the celebrated " Monday Night Meetings," where so many eminent men used to assemble, and always received a kindly greeting and welcome, whether in the New North Road, Park Street, Islington, or in his capacious museum at Highbury Grove.

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A Fellow of the Geological Society as early as 1838, he wrote a paper in the Annals and Magazine of Natural History' on "Organic Remains in the Flint of Chalk,” and in 'Trans. Geol. Soc.' vol. vi. 1841, on "Siliceous Bodies of the Chalk, Greensand, and Oolites."

He also formed a large collection of fossils, very many of which now enrich the national and other collections.

Dr. Bowerbank was one of the originators of the Zoological Society, and for many years a member of its Council.

In his museum at Highbury Grove the first idea of an aquarium was started. A small glass jar was used to keep Chara translucens for microscopical purposes, to which were afterwards added some fish and animalcules, until at length the idea was worked out by Mr. N. Ward, Mr. Warrington, Mr. M. Marshall, and others, and brought to its present state of development.

As a Fellow of the Royal Society he in 1857 contributed several papers on the "Anatomy and Physiology of the Spongiada;" but as a member of the Ray Society, which, with the late Dr. Johnston, he assisted in founding, and of which he was for many years Treasurer, he will be best known and remembered for his "Monograph of the British Spongiada."

It was in the year 1841 when occurred a fortunate opportunity which gave a bias to his future studies of the sponge, and then first began his really great work.

At Brighton a storm had thrown upon the beach vast quantities of seaweed and sponge as far as the eye could reach. Although dead, they were filled with the soft matter of the sponge. He selected the most promising specimens, placing them in glass jars filled up with strong spirit, and had them immediately conveyed to London for systematic examination, and from these he derived more information than from many times their number of dry specimens.

Having agents on many parts of the coast collecting fossils, he now also employed them in collecting sponges.

Friends in different parts of the world made consignments which were of the utmost value to him in his investigations. His general instructions were, "Only remove as much of the watery matter as will prevent the sponges from rotting on the voyage; but do not send me clean specimens, as if intended for the bath."

The accumulations of years, numbering very many hundreds, are now in the British Museum.

Dr. Bowerbank was a Fellow of the Royal and nearly all the other scientific societies of London. He died at St. Leonards-on-Sea, the 8th of March, 1877, in his eightieth year, after an illness of a little more than a month's duration, and was buried in the family vault at Hollington Church, near Hastings.

CHARLES TYLER.

PROCEEDINGS OF THE SOCIETY.

KING'S COLLEGE, December 5, 1877.

H. C. Sorby, Esq., F.R.S., President, in the chair.

The minutes of the preceding meeting were read and confirmed, donations announced, and the thanks of the Fellows were unanimously voted to the donors.

The President said it would perhaps be desirable that he should make an announcement as to what had taken place that evening at the meeting of the Council, with reference to the Journal. On account of the death of Dr. Lawson some difficulties had arisen, and Mr. Bogue proposed terms which it was out of the power of the Society to entertain. The matter had been thoroughly discussed by the Council that evening, they having met at six o'clock specially for the purpose; and after going into the question in all its bearings, it had been decided that the Society should publish its own Transactions' from January next. They thought that this plan would offer some advantages to the Fellows, and would be altogether more in accordance with the dignity of a Society like theirs. A committee had therefore been formed to carry out the new scheme.

Mr. J. E. Ingpen then read a paper by Herr Zeiss, "On Abbe's Apertometer," which was illustrated by the exhibition of the apparatus and by drawings made upon the black-board. (The paper will be found printed at p. 19.)

The President, in moving a vote of thanks to Herr Zeiss, said he had been obliged to pay some attention to this subject of angular apertures, and he felt much dissatisfied so far as his experience went, from the want of similarity in the results obtained by different methods. He thought it would be exceedingly interesting to know how far the new method agreed with the others. He suggested that it would be well to stop off the front lens of the objective by diaphragms of different sizes, so as to ascertain whether by so reducing the front they would obtain results which were consistent with those obtained in other ways. He would impress upon those who were interested in the subject, the desirability of commencing with low powers, and gradually working up through the series to the high ones. He might just add that the question was one which had been forced upon his notice by certain calculations of Professor Stokes, which caused him to try and see if the apertures as measured in different

ways would give differences sufficient to account for the discrepancies observed.

Mr. Ingpen wished to say a few words, by way of supplementing what he said after reading Mr. Wenham's paper on his new method of measuring apertures. Since that time, he had seen Mr. Wenham's way of doing it, and would endeavour to explain it more clearly than he had been able to do on the former occasion. In measuring the angle, Mr. Wenham used the object-glass without any object upon the stage, and having placed the instrument in a horizontal position, he marked off a circle having the objective in its centre; he then put over the eye-piece an achromatic observing lens, and placing a light on a level with the objective, he turned the instrument round until the light began to disappear. Having measured the arc, and marked it as zero on the circle, he turned the instrument round in the opposite direction until the light began to fade on that side; this so far was the ordinary way of measuring the angle. But then at this point he took a brass cap with a very minute hole in the centre, and put it over the eye-piece, and it was at once found that the small pencil of rays which could alone get through this hole was much less than those which got into the whole tube. He took a new-inch objective and tried to measure its angle in three ways; in the old way it showed as 125°, then on looking at it with an observing lens it seemed about the same; but the moment the cap was put on, down came the angle to 100°, and Mr. Wenham said that this was the true critical angle of the glass. The principle upon which the cap was used was then explained by means of black-board drawings, and it was shown that through the small hole they got the central pencil of rays which passed through the objective-not of course all that went through the front combination, but all that would pass through the lenses as observing rays.

Mr. Slack asked if Mr. Ingpen had compared the readings obtained in the new way with those obtained by Mr. Wenham's method.

Mr. Ingpen said he had not yet had time to do this, having only received the apparatus on the previous evening; but he had found that it did reduce the angle, although he could not say to what extent.

Mr. Stephenson, in reply to a question from the President, said that Professor Abbe had shown him the apparatus when he was in London, at the Exhibition of Scientific Instruments at South Kensington. Professor Abbe on that occasion tried several objectives; the lowest of these was Zeiss's No. 2 immersion, which gave 105°, No. 3 gave about 102°. It seemed to him to be a very excellent way; on the occasion to which he referred the slab of glass was rather different from the one now exhibited, being square instead of half circular.

Mr. Slack asked Mr. Stephenson if the measures taken by his own plan differed much from those obtained by Mr. Wenham's.

Mr. Stephenson said he had never tried Mr. Wenham's method, his remarks referred entirely to Professor Abbe's.

Mr. Ingpen pointed out that it was decidedly essential that every circle should be most accurately calculated, and that a different correction was necessary in the case of every plate in consequence of differences in the refractive indices of the glass of which they were made.

Mr. Slack then read a paper by Mr. F. A. Bedwell, "On Cephalosiphon." The paper was illustrated by drawings, some of which were enlarged upon the black-board by Mr. Stewart. Mr. Slack, in referring to the diagrams, explained briefly the structure of the rotifer, and showed that the chief point in the paper was that the selective power, which all observers must have noticed to be possessed by this class of creatures, was in some way or other connected with the "tongue."

The President moved a vote of thanks to Mr. Bedwell for his communication, remarking at the same time upon the difficulty of following papers of this kind without having them to read and compare with the diagrams at one's leisure.

Mr. W. S. Kent said that mention was made of the "siphon tube"; he thought that to be really what its name implied, it must necessarily be open at both ends, but he could not make out that this was so. It was apparently a kind of long tentacle thickly fringed with hairs at the end, and seemed more likely to be used as a plasterer's brush than a siphon.

Mr. Charles Stewart read another paper by the same author, "On a New Method of Examining Actinia mesembryanthemum ;" and at the suggestion of the President, Mr. Stewart by means of a large blackboard drawing explained the general structure of this class of seaanemones, and denoted the chief points of interest referred to in the paper.

The President proposed a vote of thanks to Mr. Bedwell for the paper, which he thought evinced a great amount of work; their thanks were also due to Mr. Stewart for his very clear explanation of the subject.

Mr. W. S. Kent regarded this as a most interesting paper, and one which he felt sure they would appreciate still more when they had an opportunity of reading it. It appeared to contain some rather original discovery, and the mode of examining these creatures was certainly very ingenious, and would enable the merest tyro to examine this species perfectly.

it

Mr. Charles Stewart said that a specimen found some time ago in a deep-sea dredging from the 'Porcupine' showed that there was not the same contraction of the body walls as was found in most species. It was at first thought to be a Holothurian. Mr. Stewart then drew upon the black-board, and pointed out that a section of it agreed in every respect with a drawing of Actinia given by Mr. Gosse. He also mentioned that observations of these deep-sea creatures did not necessarily depend upon vivisection, as recommended in Mr. Bedwell's paper, because the objects themselves were so transparent that all which went on within could readily be seen from outside. In this way the absorption of food might be perfectly watched, and it would

be seen that it was not digested in the so-called stomach, but was rapidly passed down into the body cavity below.

The President stated that he had at one time studied some of these creatures in order to ascertain the nature of their colouring matters.

Mr. Stewart said this reminded him that there was a circular band round the mouth, of a beautiful colour, which was due to the presence of hæmoglobin; and it was curious to note that this was the colouring matter of the human muscles, and it was also found in the Odontophores.

Mr. W. S. Kent inquired if the President had paid any attention to the remarkable turquoise bodies found upon Actinia, and which was also found in a jelly fish, also in a nudibranch, and in a marine Cyclops and some others.

The President said it was a number of years since he investigated these subjects, and although he believed that he did examine a blue colour amongst others, he was not prepared to say off-hand, as he was unable to recall the observation with sufficient distinctness. He was, however, quite impressed at the time with the idea that there was a wide field of research open in that direction.

The meeting was then adjourned to January 2, 1878.

The following gentlemen were elected Fellows of the Society :W. L. Scott, Esq.; James Baynes, jun., Esq.; Rev. P. R. Sleeman; and Henry Schlesinger, Esq.

Dr. John Millar, F.L.S., in the chair.

January 2, 1877.

The minutes of the preceding meeting were read and confirmed, a list of donations read, and the thanks of the meeting were voted to the donors.

The chairman reminded the Fellows that in view of the approaching anniversary meeting they would be called upon to elect two auditors of the accounts, and the "House List" of nominations for Officers and Council would be submitted to them.

Mr. W. T. Suffolk, proposed by Dr. Gray, and seconded by Mr. Thos. Palmer; and Mr. R. T. Lewis, proposed by Mr. Curties, and seconded by Dr. Matthews, were then duly elected Auditors.

The Chairman said that with regard to the changes proposed in the list of Officers and Council, the President would retire, and it was proposed to elect as President Mr. H. J. Slack. Two of their Vice-Presidents would retire, and in their places it was proposed to elect Dr. Hudson and Mr. Sorby. Their present Treasurer would be invited to retain his office, and as Secretaries they had nominated Mr. Charles Stewart and Mr. Frank Crisp. The four members of the Council who would retire were Messrs. Crisp, Ingpen, Loy, and Dr. Lawson, and it was proposed to elect in their places Messrs. Badcock, C. J. Fox, Dr. Gray, and Dr. Matthews.

A paper by Dr. Bartlett, "On the Detection of Toxic Matter connected with Typhoid and other Enteric Diseases," was read by the Secretary, and the thanks of the meeting were unanimously voted to the author for his communication.

Dr. Bartlett, in reply to a question from Mr. Slack, said that the

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