578 



SCIENCE. 



would seem, from its discovery in a lymphatic abscess by 

 Bancroft, and in a lymph scrotum by Lewis, to have a 

 peculiar aptitude lor selecting the lymph channels for its 

 habitat; a selective power not more remarkable than that 

 which urges the trichina to lodge in muscular tissue. 

 This is further borne out by the fact that its embryos — 

 the rilaria sanguinis hominis — are met with in the blood 

 and the urine of the subjects of chyluria and naevoid (or 

 lymphatic) elephantiasis. 



Now, although the various discoveries which have been 

 made — at the expense of so much patient research and 

 at such various times that, as Dr. Cobbold remarked at 

 the meeting, they form each distinct "epochs" — have 

 enabled us to form the above complete sketch of the life- 

 history of the parasite, there are lacunae still to be filled 

 up. Thus knowledge is wanted upon the growth and 

 migration of the parent worm after it has gained en- 

 trance into the human body, also as to its duration of 

 life, and particularly as to the question whether it can 

 take on the power of a sexual reproduction, and if so, for 

 how long a time. The myriads of filariae that are pro- 

 bably daily reproduced in the body of such a patient as 

 that under Dr. Mackenzie's care seem to demand such a 

 fact as alternate generations, and also to raise the ques- 

 tion as to the time during which the process of reproduc- 

 tion can continue. There is no reason to believe that the 

 embryonic filarial in the blood can undergo further deve- 

 lopment within the human body; indeed, analogy, as well 

 as the remarkable discover}- of an intermediate host in 

 the mosquito, are opposed to this notion. Again, filariae 

 have been found in the blood apart from chyluria or any 

 outward manifestation of lymphatic derangement; but 

 this is explicable if it be admitted that the adult worms 

 may ledge in other parts o*' the body in communication 

 with blood vessels alone. Conversely, chyluria may exist 

 without filaria, and the case mentioned by Dr. Mackenzie, 

 where the parasite was found in the man's blood in India, 

 but could not be found when he came to England, is 

 explicable on the view that though the parent organism 

 might have perished, or yielded no more embryos, yet the 

 change excited by its presence in the lymphatic channels, 

 and therefore the chyluria, might still have persisted. 



The precise mechanism of chyluria still requires to be 

 explained, and until it is elucidated an important part of 

 the subject will remain obscure. The question of the 

 pathology of chyluria was, however, barely touched upon 

 on Tuesday, Dr. Mackenzie limiting himself to the state- 

 ment of the tacts observed in his case ; the most im- 

 portant in connection with the urine being that besides 

 having all the chylous characters, it invariably contained 

 more or less blood, — that passed by day containing 

 more blood and filaria, that passed by night being more 

 milky ; and that filarias were found in it, especially in 

 connection with blood coagula. The most remarkable 

 feature of the whole case lay in the periodicity shown by 

 the filaria; in their time of appearance in the blood. 

 During the whole period of the man's stay in the hospital 

 his blood had been examined regularly every three hours, 

 with the constant result that, by night, the filariae 

 abounded and by day were entirely absent. From 9 A. 

 M. to 9 P.M. they were absent ; they appeared at the 

 latter hour and increased up to midnight, then decreased 

 till at the first-named hour none were found. These ob- 

 servations entirely confirmed those of Manson, and par- 

 ticular stress was laid upon their nocturnal wanderings 

 and the habits of the mosquito. It is certainly singular 

 that the time selected by the mosquito should coincide 

 with the presence of the parasite in the blood stream, and 

 the connection of these two facts is not the least wonder- 

 ful chapter in the life-history of the parasite. But what- 

 ever the explanation of the periodicity — Dr. Vandyke 

 Carter pointed out that it was not invariable, — a valuable 

 addition to our knowledge of it has been made by Dr. 

 Mackenzie. He found that whereas the time of ingestion 

 ol food bears no relation to it, it is otherwise with the 



time of rest and sleep, for when the patient was up during 

 the night and slept during the day the period of filarial 

 migration was similarly inverted. Dr. Mackenzie did not 

 venture to speculate upon these curious points. He 

 wisely contented himself with laying the facts he had 

 observed before the Pathological Society. — Lancet. 



A VERY REMARKABLE METEOR. 



On the evening of Wednesday thej6th, while sweeping 

 the western heavens in search of comets, I was startled 

 by a brilliant illumination to my right; looking up hastily, 

 a bright meteor was seen moving rapidly along the north- 

 eastern heavens. It started from a point about 3 north 

 of Capella, and, traversing a path of about io°, passed 

 some 2" above delta Auriga. The flight of the meteor 

 did not exceed three seconds, when it burst with a daz- 

 zling brilliancy, to be compared oniy to the whiteness of 

 the electric light. At the moment of exploding it must 

 have been at least five or six times brighter than Venus 

 at her maximum. There remained in its wake — covering 

 the full extent of its path — a thin reddish train ; this 

 drifted slowly among the stars towards the north-east, 

 gradually collecting into a lightish cloud at its N.E. end. 

 Noting the remarkable permanency of the train, I turned 

 the telescope (a 5-inch refractor) upon it, and was sur- 

 prised to see a very brightly glowing mass of pinkish 

 smoke ; the same material lay stretching out toward the 

 southwest in a long, straggling strip ; this trail was 

 about one-fourth a degree in thickness, and could plainly 

 be seen with the telescope for a distance of at least ten 

 degrees. This mass of smoke drifted northeasterly over 

 the stars, curling slowly, like a mighty serpent. It was 

 knotted in several places with cumulous forms which were 

 due probably to minor explosions in the meteor. The 

 outlines of this wonderful train of celestial smoke were 

 well defined ; it did not diffuse itself in the atmosphere, but 

 faded gradually from view. During the whole of its vis- 

 ibility it retained its pinkish color. The appearance of 

 the meteor was at 48m. past 6. The train remained 

 visible to the naked eye for about six minutes. In the 

 telescope it was very distinct up to seven o'clock. At 

 three minutes after seven it was still visible in the instru- 

 ment. Meanwhile it had drifted about 4° to the north- 

 east, becoming more crooked each moment as it curled 

 about in the air. The remarkable duration of the train 

 of smoke from this meteor — over fifteen minutes — de- 

 serves being recorded. E. E. Barnard. 

 Nashville, Tenn., November 21, 1881. 



INSTRUCTIONS ISSUED BY THE INTERNA- 

 TIONAL CONFERENCE FOR THE OBSER- 

 VATION OF THE TRANSIT OF VENUS OF 

 1882. 



Contributed by M. Benjamin, Ph. D. 



Article r. — It is desirable, from a theoretical stand- 

 point, that the telescopes used should be of as large ap- 

 erture as possible. In practice, the difficulty of trans- 

 portation on the one hand, and the necessity of observers 

 at different stations having similar instruments, limits the 

 apertures to from 0.12 metre to 0.15 metre (about ^% 

 to 6 inches). 



In all cases the objectives should be as perfect as pos- 

 sible. Observers should give an exact description of the 

 quality and defects of the objective, as also the eye-piece 

 employed. Towards this end they should determine: 



1. The form of the image of a good star in focus, as 

 also the image of the same star at a point before and 

 after coming into focus. 



2. The separating power of the objective for double 

 stars. 



It will be useful to know also if the telescope is able to 

 show the solar granulations on any favorable opportu- 



