ope periosteum. The two cases died, but at sufficient time after the ration to show the advantages of the remedy. Both were cases of resection of the elbow-joint. One died eighteen months and the other a year after the operation. Death of Albrecht Von Graefe.-The 'Lancet' records the death of this distinguished man. Besides some researches which may be considered to give him standing as a microscopist, he had done much to advance our knowledge of eye structure. Indeed he may safely be said to have been the first ophthalmic surgeon in the world. Death of Minute Organisms.-A paper which is of some interest, though containing many facts which are now regarded as absolutely proven by the advanced microscopist, is published in the 'Lancet,' August 6th. Mr. John Dougall, M.B., is the author, and he states that the number of genera of organisms operated on by him is undoubtedly small; still they represent a number of facts, forming a quota of the truth. The entomostraca, though not microscopic, are yet very small in size, being about th of an inch in their short diameter. These were added to the list from their being easily procured, and also for the purpose of comparing their susceptibility to the action of the poisons with that of the other organisms. A considerable number of them happened to be pregnant females, having their purple ova-sacs attached externally at the free abdominal extremity, which were soon shed or aborted under the influence of the poison. The species was exclusively Cyclops quadricornis (Müller), taken in fresh water. The infusoria were obtained from water in which hay had been steeped for two weeks. The spermatozoa were human, and regarding these it may be stated that it has been ascertained by Kölliker, quoted in the 'Cyclopædia of Natural History,' "that the over-dilution of the semen with water causes the filaments to form loops, and their motions to cease, and that they are revivified by the addition of such substances as albumen, syrup, &c." My observations on the spermatozoa have been such as to make me accept the first part of this statement with some qualification. Probably were the semen very largely diluted with water, the phenomena would be such as described by Kölliker; but it has been found that two parts of water added to one part of the spermatic fluid has only the effect of curtailing the vivacity of the filaments, considerable motion being still quite perceptible. In regard to the latter part of Kölliker's statement-namely, "that the filaments can be revivified by the addition of albumen, syrup, &c., when rendered motionless in dilute aqueous solutions," it was understood that he meant solutions which are very dilute; and as most of the substances which have been stated as causing the death of the filaments may be considered as very dilute, it was assumed that the cessation of motion might be the result of such great dilution, and consequently that, according to Kölliker, the addition of syrup or albumen would prove whether the filaments were merely motionless or actually dead. In each case, then, after it was seen that they had ceased to move, an attempt at resuscitation was made by adding a little syrup or albumen, and it may be stated that in no case was motion renewed. A uniform method in bringing the various poisonous menstrua in contact with VOL. IV. N Journal, the organisms was strictly observed. As far as practicable, a part of the poisonous solution, equal to the amount of fluid on the slide, was in every case added. It was found that when two drops of the former were added to one drop of the latter, the effect was much more marked than when equal parts were brought in contact. This was of course to be expected, two drops containing double the quantity of poison in one drop, though the degree of dilution was the same. It will be observed in the subjoined Table that the spermatic filaments are capable of existing in a very concentrated solution of common salt (th). In more dilute solutions, as th tooth, their movements are greatly accelerated. I was not aware, when experimenting with this substance, that the same effects had been observed by Quatrefages, Newport, and others. It will be observed, also, that the various poisons were allowed to act on the organisms for a uniform period of time—i. e. the spermatic filaments were kept immersed for fifteen minutes in every case; so also were the entomostraca; and though the regularity of the data is disturbed by the infusoria having been allowed only two minutes' immersion, still the relative effects of the various solutions in a given time is shown: the object being to ascertain, in the case of each distinctive poison applied separately to the different genera of organisms, the exact quantity requisite to destroy them in a definite time. TABLE SHOWING THE QUANTITY OF VARIOUS SUBSTANCES IN AQUEOUS SOLUTION REQUIRED TO KILL, IN A GIVEN TIME, SPERMATOZOA, INFUSORIA, AND ENTO A Testimonial to Professor Morris.-Professor John Morris, F.G.S., of University College, London, has received from his several admirers a testimonial and upwards of 600l. A meeting was convened on the 14th July, at the apartments of the Geological Society, Somerset House, Sir Roderick Murchison, Bart., being in the chair, supported by the President of the Geological Society, J. Prestwich, Esq., F.R.S., the Treasurer and Secretary, and a numerous assemblage of Mr. Morris's friends. An address (the wording of which had been entrusted to Prof. Phillips, F.R.S., of Oxford), beautifully engrossed and illuminated on vellum, and framed in a suitable manner, was presented to Prof. John Morris by Sir R. Murchison, together with the proceeds of the subscription, and the Silurian chieftain made a most admirable speech, in which he was followed by Mr. Prestwich, both these gentlemen being among Prof. Morris's earliest and most attached friends. In returning thanks, Mr. Morris (who was most heartily cheered) made a most touching and eloquent speech, in which he referred to his early geological labours and travels, nearly thirty years ago, in the company of Murchison and Prestwich. Mr. Prestwich afterwards read a letter just received by Mr. Hearn, the Secretary, from the venerable Prof. Sedgwick, expressing his regret that the infirmity of years prevented his being present, but assuring Mr. Morris of the cordial esteem and regard which he entertained for him and for his scientific labours. After all, the honour was long overdue. A curious Flesh Parasite has been figured in the Lancet by Dr. Tilbury Fox. It is thought, he says, to possess jaws and to bite freely; and certain of the wounds seen on the skin are regarded as having been produced by the bites of the pediculus. This is all a mistake. Prof. Schjödte has clearly shown that the pediculus is furnished with a peculiar sucking apparatus. The mouth is furnished with a labium, capable of being retracted into the upper part of the head. This lip is first inserted into a sweat-pore, and is then protruded. A row of hooks then hold to the parts around, and two pairs of setæ are next protruded and applied together so as to form a tube. When the pediculus is sucking, soon a red speck is seen at the top of the head, which exhibits dilation and contraction; and this red coloration is traced presently into and along the œsophagus and the intestines, which latter are seen to be in lively peristaltic action. The effect of the attack of the pediculus is to cause a little escape of blood into the follicle; and it appears as a minute and, at first, bright red speck, the size of a couple of pin points-not raised, not itchy, and not removable by pressure. Occasionally some swelling takes place; but this quickly subsides. NOTES AND MEMORANDA. Continuously Adjustable Diaphragm.-Mr. J. Zentmayer, of Philadelphia, U.S., some time since devised and constructed a diaphragm, of which the accompanying woodcuts are views in two conditions of adjustment. €3,98 Two cylinders or rollers of equal size and parallel axes are so mounted as to be revolved in contact by fine gearing at one end. Similar conical grooves are arranged in the surfaces of these in such a manner that they produce together a circular opening, which will of course vary its size according to the position of the cylinders in their revolution. There is theoretically an objection to a diaphragm of this construction, from the fact that its opening will not be always in the same plane. With the largest opening, the smallest section at right angles to the line of sight will be nearest to the plane passing through the axes of the cylinders, and with the smallest opening it will be farthest from this plane. This difference is, however, very small in fact, and might in certain cases become advantageous. CORRESPONDENCE. DR. PIGOTT AND MR. WENHAM. To the Editor of the Monthly Microscopical Journal.’ ASHDOWN COTTAGE, FOREST Row, Sussex, DEAR SIR,—I am sorry to find, from Mr. Wenham's letter in your last number (July), that I helped to mislead him concerning Dr. Pigott's experiments, by speaking of the microscope being converted into a telescope. I did not mean used as a telescope, but as Dr. Pigott's method is explained in the Proceedings of the Royal Society,' to which you have referred, I need not now say more on this subject. 6 I hope Mr. Wenham will before long have an opportunity of fully testing Dr. Pigott's statements concerning aberration, as if he, Mr. Wenham, is once convinced that any mischievous amount of error exists in our best objectives, his remarkable practical skill will be immediately directed to the best method of cure. He is of all men the most likely to be successful in this difficult matter. I remain, dear Sir, Yours faithfully, HENRY J. SLACK. PROCEEDINGS OF SOCIETIES.* QUEKETT MICROSCOPICAL CLUB.† The annual meeting was held at University College, July 22nd, 1870, P. Le Neve Foster, Esq., M.A., President, in the chair. The fifth annual report, read by the Secretary, warmly congratulated the members upon the continued success and usefulness of the club, whose members now exceeded 500, 57 having joined during the year. The cabinets contained upwards of 1300 slides, and important additions had been made to the library. Especial reference was made to the courtesy and kindness of the authorities of University College, by whose permission the meetings of the club were held in that building. The Treasurer's report showed a balance in hand of 267. 9s., and the report of the Librarian detailed the additions made in his depart * Secretaries of Societies will greatly oblige us by writing their reports legibly -especially by printing the technical terms thus: Hydra-and by "underlining words, such as specific names, which must be printed in italics. They will thus secure accuracy and enhance the value of their proceedings.-ED. M. M. J. + Report furnished by Mr. R. T. Lewis. |