March 27, 1891.] 



SCIENCE. 



173 



struetion of the rod. Would it not be more logical, iu considera- 

 tion of what we know of the conservation of energy, to say that 

 the saving of damage to the building was on account of the de- 

 struction of the rod V The editor of Science will be glad to receive 

 and publish pertinent accounts of lightning-stroke, that this con- 

 troversy may be cleared up. But it should be borne in mind that 

 a dissipated rod can protect only such points as lie between hori- 

 zontal planes passing through its upper and lower ends, since the 

 electrical energy comes in horizontally from the dielectric around. 



— During the months of July and August, 1891, the following- 

 named courses of instruction will be given in the summer schools 

 of Harvard University: Anglo-Saxon, English, German, French, 

 chemistry (4 courses), botany, geology (3 courses), physics (3 

 courses), physiology and hygiene, field-engineering (3 courses), 

 physical training, and also a course of about thirty lectures con 

 cerning the methods of instruction in the several departments in 

 which these courses belong. All of the above-named courses, 

 except the two advanced courses in geology and those in field-en- 

 gineering, are given in the college buildings at Cambridge, and are 

 open to both men and women. The course in physiology and 

 hygiene is expressly designed to meet the needs of teachers in the 

 public schools. For information concerning the summer instruc- 

 tion in medicine, application should be made to the dean of the 

 Harvard Medical School, Boylston Street, Boston, Mass. For 

 circulars describing each of the summer courses in detail, appli- 

 cation should be made to the secretary of Harvard University, 

 Cambridge, Mass. 



— As various erroneous statements have been made with regard 

 to Dr. Nansen's Arctic expedition, the London Times gives the 

 following account of what has actually been arranged. Dr. 

 Nansen's desire is to leave Norway in February, 1892, but it is 

 doubtful whether the special vessel which is being built will be 

 ready by that time. Outside of Norway, not a farthing has been 

 contributed by any one. The expedition is purely Norwegian, and 

 will remain so. The Norwegian Government contributed 200,000 

 kroner; King Oscar, 20,000; twelve private individuals (all Nor- 

 wegians except one Englishman, who has lived in Christiania for 

 many years), 90,000: in all, 310,000 kroner, equal to £17,300. 

 That, Dr. Nansen believes, will be sufficient. The ship, of course, 

 is being specially constructed for the peculiar conditions which 

 exist between the New Siberian Islands and the Pole. Dr. Nansen 

 will be accompanied by probably not more than eight young men, 

 all as stalwart and strong in physique as himself, and all equally 

 confident of success. 



— It has been shown by Dr. Marcet, according to Nature of 

 March 12, that different persons respire different volumes of air 

 to furnish to the body the oxygen required, and to yield a given 

 weight of carbonic acid. Thus, to produce one gram of carbonic 

 acid, three persons were found to need, on an average, 9 29, 10.51, 

 and 11.30 litres of air respectively. The first was 23 years of age, 

 the third 60 ; and no doubt the less the air required for a given 

 combustion, the better the conditions of respiration. Tl)e influence 

 of food on formation of carbonic acid in the body begins in the 

 first hour after a meal, and increases for two or three hours, the 

 period of maximum respiration of COj varying in this time. After 

 a certain time, the weight of C0„ expired decreases more rapidly 

 than the required volumes of air decrease. The influence of local 

 variations of air-pressure appears in less air being needed, for a 

 given amount of COg, with low pressures than with high; but the 

 degree of the influence varies in individuals. 



— It may be well to call attention again to the Royal Society 

 of New South Wales prizes for original researches. The prizes 

 are for thte best communication (provided it be of sufficient merit) 

 containing the results of original research or observation upon 

 each of the following subjects: to be sent in not later than May 1, 

 1892, on the iron-ore deposits of New South Wales, the society's 

 medal and £35 ; on the effect which settlement in Australia has 

 produced upon indigenous vegetation, especially the depasturing 

 of sheep and cattle, the society's medal and £35; on the coals and 

 coal-measures of Australasia, the society's medal and £25 : to be 

 sent in not later than May 1, 1893, upon the weapons, utensils. 



and manufactures of the aborigines of Australia and Tasmania, 

 the society's medal and £25; on the effect of the Australian cli- 

 mate upon the physical development of the Australian-born pop- 

 ulation, the society's medal and £35; on the injuries occasioned 

 by insect pests upon introduced trees, the society's medal and £25. 

 The competition is in no way confined to members of the society, 

 nor to residents in Australia, but is open to all without any re- 

 striction whatever, excepting that a prize wiU not be awarded to 

 a member of the council for the time being; neither will an 

 award be made for a mere compilation, however meritorious in 

 its way. The communication, to be successful, must be either 

 wholly or in part the result of original observation or re- 

 search on the part of the contributor. The society is fully sensi- 

 ble that the money value of the prize will not repay an investiga- 

 tor for the expenditure of his time and labor, but it is hoped that 

 the honor will be regarded as a sufficient inducement and reward. 

 All communications should be addressed to the honorary secreta- 

 ries, 5 Elizabeth Street, Sydney, New South Wales. 



— Some interesting remarks on squirrels are made by various 

 writers in the Zoologist. It is often said that squirrels are torpid 

 during winter, but there is no really sound evidence for this view. 

 Mr. Masefield, writing from Cheadle, Stafford, Eng , says {Nature, 

 March 13), " I have seen squirrels abroad on fine days in, I think 

 I may say, every one of the winter months ; and while pheasant- 

 shooting near hei'e on a sunny day (Jan. 6 last), which was about 

 the middle of the most severe frost we have had for many years, 

 with several inches of snow on the gi-ound, I saw a squirrel jump- 

 ing from tree to tree, before the beaters, in the most lively con- 

 dition." Mr. Blagg, also writing from Cheadle, has "frequently 

 seen squirrels abroad in the middle of the winter, when there has 

 been deep snow on the ground and a keen frost in the air. I re- 

 member," he adds, "once seeing a squirrel abroad during a severe 

 storm of sleet and rain in winter-time, and he appeared to be 

 not at all inconvenienced by thorough weather." Mr. Blagg's idea 

 is that the squirrel probably does sleep a good deal more in winter- 

 time than iu summer, as do many other wild animals, but that he 

 has to be continually waking up and taking nourishment. The 

 period of reproduction is unfavorable to the notion of an almost 

 complete state of torpidity. The editor of the Zoologist records 

 that he has notes of '' finding newly-born squirrels on March 21 

 (three young), April 9 (three young), April 26 (four young), and 

 April 29 (two young). Those found at the end of March and be- 

 ginning of April were naked and blind ; those taken at the end of 

 April were about three parts grown." According to the editor, 

 "the old squirrels, in case of danger, remove the young from the 

 nest, or ' drey,' to some hole in a tree, whither they carry them 

 one by one in the mouth, just as a cat carries her kitten. One of 

 the prettiest sights in the world is to see an old squirrel teaching 

 a young one to jump." 



— Professor Dubois of Berne, as we learn from Nature of March 

 13, has lately been studying the physiological action of electric 

 currents and discharges; and he has some interesting observations 

 on the human eye, which, it is known, has luminous sensations 

 under the action of galvanic currents. Sudden variations of in- 

 tensity, especially at making and breaking the circuit, produce 

 such flashes. With a moistened plate at the nape of the neck, 

 and a pad on the eye, a slight flash was distinctly perceived, even 

 with a Leclancbe cell of about 1.20 volts, and measuring in the 

 galvanometer .04 of a milliampere. Raising the intensity to .5, 

 the observer could tell which pole was applied to the eye. On the 

 other hand, the retina responds much less readily to discharges 

 from condensers or induction coils. Not till a capacity of 0.087 

 of a microfai-ad and a tension of 31 volts was reached was a true 

 retinal flash perceived ; and not even with 10 microfarads were the 

 durable sensations characteristic of the two poles produced. The 

 retina re-acts to quantity. 



A new quarterly journal is announced for publication by 



Macmillan & Co., The Economic Journal, issued under the 

 auspices of the British Economic Association, a society which 

 numbers among its members Professors R. M. Smith of Columbia, 

 Taussig of Harvard, Alfred Marshall, Henry Sidgwick, and many 

 others equally well known. 



