452 



NA TURE 



\_AIairh lo, 1887 



Topaz Butte, five miles north of Florissant, marks the southern 

 limit of the "crystal beds" whence have come most of the 

 specimens labelled Pike's Peak. The largest phenacite ever 

 found in this locality is a rough lenticular crystal about 15 mm. 

 in diameter. — The noiites of the Cortlandt series on the Hudson 

 River, near Peekskill, New York, by George H. Williams. In 

 continuati in of his memoir on the peridotites of the Cortlandt 

 series {American Journal of Science, 1886, p. 26) the author 

 here begins a petrographic description of the massive rocks of 

 this system. The present paper deals with the non-chrysolitic 

 rocks, norite proper and hornblende norite. He designates all 

 rocks in which one-half or more of the non-feldspathic con- 

 stituents are hypersthene as norite, and names varieties of this 

 after the prevailing accessory compment. — .\ method for subject- 

 ing living protoplasm to the action of difterent liquids, by George 

 L. Goodaie. An apparatus is described by means of which the 

 necessity is obviated of transferring specimens from the litre- 

 flask to the stage of the microscope, all handling being thus 

 avoided, while the object can be placed under the action of as 

 large a quantity of liquid as may be desirable. — On the topaz 

 from the Thomas Range, Utah, by A. N. Ailing. The topaz 

 crystals here under examination are from the cabinet of Prof. 

 Brush, vary in length from 3 mm. to 10 mm., and are 

 perfectly clear and colourless. — On a simple and convenient 

 form of water battery, by Henry A. Rowland. A simple, con- 

 venient, and cheap form of water battery is descrilied, which 

 the author has had in use for many years. 



Bullelin ties Sciences Matheinatiqiies, tome x. December 1 886, 

 tome xi. January 1887, Paris. — -We single out these two recently 

 issued parts, as they contain papers on subjects intimately con- 

 nected with notices of Greek geometry, which we have from 

 time to time communicated to Nature when giving an account 

 of Dr. AUman's contributions to Hermathcna. In the 

 Melanges of the earlier number M. Paul Tannery has two notes : 

 one of nine pages, entitled " Democrite et Archytas" (see 

 Gow's " History," p. 129, and Nature, vol. xxxiv. p. 548) ; 

 the other, of eleven pages, on " Les Geometres de 1' Academic." 

 The later part has an article of, twelve pages, by the same 

 writer, on " La Technologic des Elements d'Euclide." All three 

 are quite up to M. Tannery's well-known excellent form for 

 thoroughness of research and soundness of inference. The rest 

 of the matter consists as usual of reviews {inter alia, of the French 

 translation of Clerk Maxwell's " Electricity and Magnetism " 

 and Mr. Greenhill's "Differential and Integral Calculus"), and 

 of useful abstracts of papers in the various Continental and 

 British mathematical journals. 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, p'ebruary 24. — " Problems in Mechanism 

 regarding Trains of Pulleys and Drums of Least Weight for a 

 given Velocity Ratio." By Prof. H. Hennessy, F. R.S. 



As trains of wheels, pulleys, and drums are frequently employed 

 in machinery for the transformation of large and small velocities 

 of rotation, it appeared to the author desirable to inquire into 

 the conditions which would favour the greatest economy of weight 

 of the parts forming such trains. Eighty years since Dr. Thomas 

 Young had arrived at a theorem for the minimum number of 

 teeth in a train of wheels and pinions with a given velocity ratio, 

 and when the pairs of wheels and pinions are similar. By 

 investigating the question of minimum volume or minimum 

 weight of trains the author has been led to the following 

 results, which are fully demonstrated in his paper : namely, that 

 for a train of cylindrical pulleys composed of similar pairs the 

 ratio of the diameter of a large to that of a small pulley should 

 be as 19 to 10. For drums composed of hoops supported by 

 disks of the same thickness, and with the breadth of each hoop 

 equal to the radius of the small drum, the ratio of the diameters 

 should be II to 5. If the hoop was supported by spokes whose 

 volume taken together would be half the volume of a complete 

 disk, the ratio would be 51 to 20. With regard to a train of 

 pulleys, it was shown that a .-ingle pair possessing the same 

 velocity ratio as a series with the ratio of diameters found for 

 minimum volume, the latter would be considerably less than the 

 former. Thus, with five pairs whose velocity ratio would he nearly 

 21^, the volume would be less than the 1/26 of a single pair 

 possessing the same velocity ratio. A model constructed in brass 

 of such a train, with all the large pulleys i'9 inches in diameter, 



and all the small i inch, weighed l8'34 ounces. A train of four 

 pairs of drums illustrative of the last problem solved weighed 

 16788 ounces, the large drums being 2'55 inches, and the small 

 I inch diameter, while all the hoops were half an inch broad. 

 The velocity ratio of this train is 42 '2825, or a little more 

 than 42J. 



March 3. — "The Etiology of Scarlet Fever." By E. Klein, 

 M. D., F.R.S., Lecturer on General Anatomy and Physiology at 

 the Medical School of St. Bartholomew's Hospital, London. 



The investigation, the results of which I now record, was com- 

 menced at the end of December, 1885. It arose out of an 

 inquiry into the prevalence of scarlatina in different quarters of 

 London, undertaken by the Medical Department of the Local 

 Government Board as a part of its business of investigating local 

 epidemics. That inquiry had demonstrated milk from a farm at 

 Hendon as the cause of the scarlatina, and had adduced strong 

 circumstantial evidence that the scarlatina had been distributed, 

 not in the whole, but in certain sections of the Hendon milk, and 

 further that the ability of the sections of milk service to convey 

 the disease had been related to a malady affecting particular cows. 

 This evidence against particular cows at the Hendon farm could 

 not and did not aim at furnishing direct and definite proof 

 of the connection of this cow disease with scarlet fever 

 of man, for the inductive methods usually employed by the 

 Medical Department of the Local Government Board when 

 applied to inquiries about epidemic spread of scarlatina can for 

 obvious reasons yield but circumstantial evidence. As on various 

 former occasions, so also on this, the Medical Department sought 

 to put the above conclusions to the test of scientific experiment. 

 Phis task was delegated to me by the Board. The first part of 

 this work has been published in the recently issued volume of the 

 Reports of the Medical Officer of the Local Government Board 

 for 18S5-86. I have therein shown that the suspected cows 

 from the Hendon farm that had been made the object of special 

 study, showed besides a skin disease — consisting in ulcers on the 

 udder and teats, and in sores and scurfy patches and loss of hair 

 on different parts of the skin — also a general disease of the 

 viscera, notably the lungs, liver, spleen, and kidney, which 

 resembled the disease of these organs in acute cases of human 

 scarlatina. I have further shown that the diseased tissues of the 

 ulcers on the teats and udder produced on inoculation into the 

 skin of calves a similar local disease, which in its incubation and 

 general anatomical characters proved identical with the ulcera- 

 tion of the cow ; and further, that from the ulcers of the cow a 

 species of micrococcus was isolated by cultivation in artificial 

 nutritive media, which micro-organism in its mode of growth on 

 nutritive gelatine, on Agar-Agar mixture, on blood serum, in 

 broth, and in milk, proved very peculiar and different from other 

 species of micrococci hitherto examined. With such cultivation 

 of the micrococcus I have produced by subcutaneous inoculation 

 in calves a disease which in its cutaneous and visceral lesions 

 (lung, liver, spleen, and kidney) bears a very close resemblance 

 both to the disease that was observed in the Hendon cows as 

 well as to human scarlatina. 



The second part of the work, carried out during 1886-87 

 for the Medical Department, had for its object to investigate 

 whether or no the disease, human scarlatina, is associated with 

 the identical micrococcus, and whether this, if ol.'tainable from 

 the human subject, is capable of producing in the bovine species 

 the same disease as was observed in the Hendon cows and in the 

 calves experimented upon from the latter source. The definite 

 and clear proof that this is really the case has now been obtained, 

 and the evidence I now bring to the notice of the Royal Society. 



On examining acute cases of human scarlatina — for which 

 opportunity I owe great thanks to Dr. Sweeting, the Medical 

 Superintendent of the Fulham Fever Hospital — I soon ascertained 

 the fact that there is present in the blood of the general circulation 

 a species of micrococcus, which on cultivation in nutritive 

 gelatine, Agar-Agar mixture, blood serum, and other media, 

 proved to be in every respect identical with that obtained from 

 the Hendon cows. Out of eleven acute cases of scarlet fever 

 examined in this direction, four yielded positive results : three 

 were acute cases between the third and sixth d.ay of illness with 

 high fever temperature, and the fourth was a case of death from 

 scarlatina on the sixth day. In all these four cases several drops 

 of lilood were used, after the customary methods and under the 

 required precautions for establishing cultivations in a series of 

 tubes containing sterilised nutritive gelatine, and generally only 

 a very small numl er of these tubes revealed after an incubation 

 of several days one or two colonies of the micrococcus. This 



