i66 



NATURE 



\7uly I, 1875 



aneroid fell 0*49 inch, the temperature was again found to be 

 98° '3 ; pulse, 116; time, loh. 42m. Twenty-three minutes 

 later, after rapid walking (barometer 0-48 inch lower than 

 previous reading) the observations were : First minute, 96° "3 ; 

 second, 97° "4 ; third, 97°"6 ; fourth, 97°7 ; fifth, 97° "8 ; pulse, 

 11 6. At I2h. 4m., after continuous walking at a good speed, 

 the observations were : First minute, 94 '2 ; second, 96°'2 ; 

 third, 97° -4 ; fourth, 97° '8 ; fifth, 98°-! ; pulse, 128. The pace 

 was now quickened almost to exhaustion, and at 2-30 p.m., 

 when greatly fatigued, the observations were : First minute, 

 93°'9 ; second, 95° 6; third, 96° "8; fourth, 97° "4 ; fifth, 98' 'O; 

 pulse, 90. These last observations were made with some diffi- 

 culty, and under such circumstances that I am disposed to attach 

 less weight to them than to the former readings. My exhaustion 

 was doubtless 'partly due to hunger, for I purposely fasted in 

 order to test the correctness of Lortet's statement that the fall in 

 temperature is specially marked during an ascent made when 

 hungry. 



These observations were all I could obtain, as I was too much 

 fatigued to carry on the work. They are scarcely numerous 

 enough to enable any very definite conclusions to be drawn ; but 

 so far as they go, they certainly are not confirmatory of the con- 

 clusions arrived at by Drs. Marcet and Lortet ; they at least 

 prove that if any decrement does occur during climbing, it is 

 never so great as 8° (Lortet), or even as much as 3° (Marcet). 



It may be thought that the low readings obtained in the later 

 observations on first placing the thermometer in the mouth, are 

 indicative of a decrease in body-temperature. It must be borne 

 in mind, however, that, especially in the later observations, we 

 were facing a keen wind sweeping down a mountain partially 

 covered with snow ; it is perfectly obvious from this cause that 

 the first minute's observations can afford no reliable indication 

 of the temperature of the mouth, or otherwise the body must 

 recover its normal temperature with a rapidity which would be 

 perfectly extraordinary. From repeated trials made on myself 

 and others, I have come to the conclusion that observations of 

 the temperature of the mouth taken even after the end of the 

 second minute give no trustworthy indication of the temperature 

 of the body ; such indications are of no value even as compara- 

 tive measurements. 



As it seems quite certain that any variation which may occur 

 is a matter of tenths and not of whole degrees, it may be 

 well to point out a source of error in the method of observation 

 which seems to have escaped the attention of observers hitherto, 

 but which in any case is too considerable to be neglected, 

 although it would specially affect the results obtained at high 

 altitudes. In taking the temperature of the mouth on a moun- 

 tain, surrounded by. a rapidly moving atmosphere at a tempera- 

 ture often but little higher than that of melting snow, it is obvious 

 that the mean temperature of the mercurial column must be 

 considerably lower than that of the mouth, since the greater 

 portion of the stem is in the cold air. The correction to be 

 added to the readings is readily calculated if we know the 

 length of the exposed column, its mean temperature, and the 

 apparent expansion of mercury in glass. If we suppose the 

 length of the exposed column in the observation taken at 

 2.30 P.M. to be forty times the length of a degree, and its mean 

 temperature that of melting snow, the correction to be added 

 to the last reading would amount to a quarter of a degree. 



The whole subject unquestionably merits reinvestigation. A 

 much larger number of observations is needed ; these should be 

 made under similar circumstances on different persons, for it 

 may well happen that the bodily idiosyncrasy of the individual 

 may affect the result. Possibly some Alpine party may under- 

 take the solution of the problem during the present season. It 

 is doubtless not so simple as it may at first sight appear. From 

 my experience during the ascent of Etna, and from what I have 

 been able to glean of the manner in which other observations 

 have been made, it seems clear that the conditions necessary to 

 obtain perfectly comparable results have yet to be determined. 

 Should any variation be observed, either in the direction observed 

 by Drs. Marcet and Lortet or in that indicated by the experi- 

 ments of Dr. Forel, it would be specially interesting to deter- 

 mine how quickly the human body recovered its normal tem- 

 • perature on re»ting. T. E. THORPE 



Arctic Marine Vegetation 



In Nature, vol. xii. p. 55, an interesting article on the 

 Arctic marine vegetation, (juotes Ruprecht (with doubt as to 



his accuracy) in regard to an asserted absence of Algse in Behring 

 Sea and the waters north of it. 



That doubt is well founded, as I can testify, having been 

 engaged during a large part 01 ten years in explorations of that 

 region. The line of the Aleutian Islands from east to west is 

 girt with seaweeds, which are quite as abundant on the north 

 as on the south side of this archipelago. If Ruprecht, however, 

 referred to the waters still further north, he is equally in error. 

 Unfortunately I am not possessed of much more botanical know- 

 ledge than comes from collecting for my botanical friends, and to 

 them I must leave the task of enumerating the species, but per- 

 haps a few remarks on the general distribution of the Algte of 

 this region may not be without interest. It is noteworthy that 

 fine and beautiful seaweeds, such as are used for ornamental 

 albums, are comparatively quite rare on the whole coast, from 

 the Vancouver Archipelago north and west. Rhodosperms are 

 particularly scarce in individuals, though how far this may be 

 true of species I am not competent to say. Chlorosperms are 

 confined to a very small number of forms, also rare as indi- 

 viduals. The great mass of the algoid vegetation of this region 

 is made up of Melanospermte. 



Some forms which I believe are closely related to if not iden- 

 tical with Fucus vesiculosus, are found in masses on the rocky 

 shores of Behring Sea, from the Aleutian Islands north to 

 Behring Strait, and I do not know how far beyond. 



The distribution of the Algce seems to be largely dependent 

 upon the character of the rocks. Basaltic shores are least rich 

 and afford few forms, except what I have called F. vesiculosus, 

 and species of Agarum. Granitoid rocks and Tertiary sand- 

 stones and conglomerates always afford at least a few forms of 

 red and green seaweeds, while on the metamorphic slates and 

 porphyritic rocks, which make up the greater part of the Aleutian 

 chain, the Nereocystis, Laminaria, Nullipot'es, and Agarum seem 

 to find their most congenial home. The character of Behring 

 Sea is unfavourable for the growth of seaweeds. Much of the 

 eastern plateau is of soft sticky mud or fine clean black volcanic 

 sand, affording no hold for Alga;. But wherever there are 

 rocks Algce may be found, though the more delicate kinds are 

 always rare. Jointed and incrusting stony Alga^ are abundant 

 on most of the Aleutians, and I have noticed them also at the 

 Pribiloff group, Nunivak, Norton Sound, and Plover Bay in 

 East Siberia, though less common northward. 



The "bull-head kelp" (Nereocystis?) is excessively abundant 

 in the Aleutians, and extends north to Nunivak and the Pribiloff 

 Islands, There is a patch of twenty-five square miles in extent, 

 north-east of St. George Island, on a shoal in the open sea. I 

 do not recollect its occurrence further north than Nunivak. 

 Laminaria extends to the Straits, and possibly north of them, 

 with Agarum, the two most abundant seaweeds of Behring Sea, 

 F, vesiculosus everywhere where there are rocks ; also a flat, 

 leathery, thick-fronded alga with short stalks, which the sailors 

 call "devil's aprons." These have the edges variously cut or 

 indented, though some forms are oval, with two thickened mar- 

 ginal bands extending outward from the stalk. In Norton 

 Sound, in 1865-66 and 1867, I obtained what seemed to me 

 to be at least fifteen or twenty species of algae, which included 

 something that I could not distinguish from the "Iceland 

 moss " of the coasts of New England, and which was not found 

 further south. In many places where the bottom was unfavour- 

 able for alga2 I have found dead shells and living Crustacea 

 entirely hidden under a growth of red and green algce, which, 

 without exercising great care, would often have, led to the rejec- 

 tion of valuable specimens of invertebrates from the dredge, 

 from their being taken for mere bundles of seaweed. 



I may also mention that in the hot springs (iio°-i8o° F.) 

 which exist on the peninsula of Alaska and many of the islands, 

 there is invariably a leathery brown algoid, covering the bottom 

 of the basins in which the springs occur. Nostoc also flourishes 

 in the fresh waters emptying into Norton Sound. I have many 

 times noticed the F, vesiculosus apparently flourishing in lagoons 

 where the water was barely brackish to the taste, and to which 

 the sea had no access except in extraordinary storms such as 

 might occur once or twice in a year. 



Much of the above may be without interest to the scientific 

 botanist; I leave it to your judgment what to reject, but I think 

 that there is no further necessity for disproving the error into 

 which Ruprecht has in some way been led ; certainly, if he had 

 himself walked the beaches of Behring Sea, where any rocks 

 exist, he could not have come to such a conclusion, 



Wm. H. Dall 

 Smithsonian Institution, Washington, D.C, U.S,, June lo 



