338 



SCIENCE. 



[Vol. XVII. No. 437 



feed-water to about Iiaif that proportion, for ratios of expansion 

 approximating six ; from one-third to about one-tenth, at a ratio 

 of five; and apparently from twenty to ten per cent at 4.4. In 

 this first case, also, the jacket gives best results, with 110 pounds 

 of steam, when the ration of expansion approximates six. When 

 the steam pressure falls to approximately eighty pounds, the best 

 work of the jacket occurs at a ratio not far from 4.75; while, at a 

 pressure of fifty pounds, the value of the jacket increases through 

 the whole range of the experiments, and not only so, but the in- 

 dications are of probable improvement indefinitely in the direction 

 of increasing expansion. The highest efficiencies, however, either 

 with or without the jacket, are found, in this case, at the lowest 

 ratios adopted, and indicate a maximum value at about 3 25. The 

 ratios of expansion for maximum efficiency of fluid, in the other 

 cases, are for 110 pounds, about five, and for eighty pounds, abou.t 

 3 5. Similarly studying the performance of the condensing en- 

 gine, we find that the best work is done, whether jacketed or not, 

 at about a ratio of expansion of ten (at a steam pressure of 110 

 pounds), but that the jacketed engine reduces the internal wastes 

 from fifty per cent at highest ratios, and from one-fourth at the 

 lowest ratios, in the case of the unjacketed engine, to live per cent, 

 and, in some cases, probably to within the magnitiide of the errors 

 of observation, At a pressure of ninety pounds the best ratio 

 seems to be for this engine, under the given conditions of opera- 

 tion, about 6.5 when unjacketed, and 8.5 jacketed; while the 

 lower pressures still further reduce both the efficiencies and the 

 savings effected by the jacket. The best work of the jacket, as 

 an economizer of heat, is done at high pressure, at a ratio of ex- 

 pansion of twelve or moi'e. In all cases it seems to be the fact, 

 with these engines at least, that the jacket is useful beyond the 

 ratios of maximum efficiency of fluid. The compound engine ex- 

 hibits the same general effects which have been noted in the cases 

 of simple engines. This discovery of a maximum efficiency of 

 jacket may throw some light upon the causes of the conflicting 

 and sometimes apparently irreconcilable results of trials of engines 

 with and without jackets, and with jackets variously constructed. 

 The discovery may also prove of value to the designer, as aiding 

 him in securing the best proportions and arrangement of his en- 

 gine. 



THE PREVAILING FEVERS OF CHINA. 

 Dr. Coltman, writing in the Medical Missionary Journal upon 

 the fevers of China, remarks, says the Lancet, that but little per- 

 sonal investigation on the subject has been made up to the present 

 time, owing to the comparatively recent advent of foreign medical 

 men, and to the want of confidence on the part of natives to sub- 

 mit for any lengthened period to the treatment of a foreign phy- 

 sician, or, in fact, to any one physician, their rule being to change 

 doctors two or three times a day if they can afford it. Again, 

 there have been but small hospital facilities for studying fevers, 

 and there is an impossibility of obtaining post-mortem examina- 

 tions. Dr. Coltman considers that smaU-pox is the most common 

 disease, nearly every person suffering from it at some period of 

 his or her life. Vaccination, altliougb practiced, is done very 

 carelessly. Measles appear to be common, but are somewhat 

 milder than in Europe. Scarlet-fever, although it undoubtedly 

 occurs among the natives, is far less common than among Euro- 

 peans. Erysipelas is rare. Typhoid-fever is very difficult to 

 diagnose in the short time that a foreign medical man is allowed 

 to attend a case; but Dr. Coltman thinks that when more accurate 

 reports are possible, this disease will be found to be more common 

 among the natives than is now supposed. Typhus-fever is met 

 with all over North China, and as far south as Shanghai. Re- 

 lapsing fever is found constantly associated with typhus. Dengue 

 does not seem to be known among natives. Cholera occurs as an 

 epidemic every few years, and is very fatal. Diphtheria is severe, 

 and frequently fatal among the natives. Whooping-cough has 

 occasionally been met with. Rheumatic fever is very prevalent in 

 some parts. Chronic muscular rheumatism is common all over 

 China, but is unattended by fever. Malarial fevers appear to be 

 common everywhere, though the prevailing type varies; thus, 

 tertian is most common in Pekin, quartan in Foochow, Swatow, 

 Shanghai, and Hangchow, and remittent in Cheefoo and Tientsin. 



In Chinanfu, Dr. Coltman has never seen a case of quartan ague; 

 it is all intermittent of the tertian or quotidian type. The treat- 

 ment, of course, of all malarial fever is by quinine or some other 

 cinchona bark alkaloid. In Hangchow the carbolic acid and 

 iodine treatment has been used successfully as a prophylactic;, 

 arsenic is recognized as valuable in the chronic form. 



NOTES AND NEWS. 



The trustees of the University of Pennsylvania have elected 

 Dr. George A. Peirsol, professor of anatomy; Dr. Harrison Allen, 

 professor of comparative anatomy; and Dr. John B. Deaver, assist- 

 ant professor of applied anatomy. 



— Mr, Emil Theilman, a graduate of the Missouri State Uni- 

 versity, has been appointed to a position as aide on the State Geo- 

 logical Survey. 



— Professor Henry S. Munroe is to have charge of the Colum- 

 bia College School of Mines' summer school of surveying at Litch- 

 field, Conn. 



— Professor J. F. Kemp of Cornell University, Ithaca, N.Y., 

 has been appointed adjunct professor of geology at Columbia Col- 

 lege, New York. 



— The Engineering and Min ing Journal of this city states that 

 extensive deposits of onyx have been discovered neijr Marion, 

 Smyth County, Va. Four openings are reported to have been 

 made so far. The stone is said to be of excellent quality. 



— The Marine Laboratory of the Johns Hopkins University will 

 be open this summer at Port Antonio on the north-east coast of 

 Jamaica. Professor Brooks and a number of members of his party 

 have already started for the station. 



— A writer in Science Oossip says that the philosopher Kant 

 one day was passing a cei'tain building in his daily walk, and on 

 looking up, he discovered, as he fancied, that the old birds were 

 actually throwing their young ones out of the nests. It was a 

 season remarkable for the scarcity of insects, and the birds were 

 apparently sacrificing some of their progeny to save the rest. 



— The hai'bor of Salonica, says the Scottish. Geographical Mag- 

 azine, is threatened with the same fate as that which has befallen 

 Smyrna. Owing to the alluvial deposits of the Vardar, the harbor 

 is becoming useless as a trading port. The entrance through the 

 sandbanks is very difficult, and the delta of the river has advanced 

 to the neighborhood of Cape Kara-Burun. The prospective value 

 of Salonica to Austria-Hungary may therefore be questioned. 



— The recent census of Bengal, says the London Times corre- 

 spondent, in a dispatch of March 37, throws an instructive light 

 on the sanitary condition of the province. The districts showing 

 a decrease in population are mainly those where defective subsoil 

 drainage produces malaria. This is especially marked in parts of 

 Nadiya and Jessor, and is due to the fact that the natural drain- 

 age channels have been blocked by injudicious cultivation, and 

 the want of sufficient provision for a water-way in the construc- 

 tion of the railway. 



— We learn from the Scottish Geographical Magazine that Dr- 

 Konrad GauzenmilUer has published in the Zeitschrift fur wissen- 

 sehaftliche Geographie (Bd. viii., Heft 1) a_ learned and able pa- 

 per illustrating his hypothesis that the Ukerewe, or Victoria 

 Nyanza, is identical with the Eastern Nile sources of Ptolemy, 

 with the Crocodile Lake of an unknown Greek writer, and with 

 "Kura Kavar" of the Arabs, and that fairly accurate knowledge 

 of the territory of the Nile sources was. formerly possessed, but 

 subsequently was lost. 



— The collections of fishes made by the " Albatross " in 1887- 

 88, at the Galapagos Islands and in Panama Bay, were reported 

 on by Jordan and Bollmann in the "Proceedings of the United 

 States National Museum," 1889, pp. 149-183. A small portion of 

 the collection, however, failed to reach the authors in time for their 

 report, and has now been listed by Charles H. Gilbert, professor of 

 geology in the University of Indiana. The supplementary list is 

 noteworthy as containing the remarkable new genus Dialommus,. 

 which repeats in the Blenniidce the peculiar structure of the eyes- 

 seen in the Cyprinodont genus Auebleps. 



