June 24, 1S80] 



NATURE 



187 



Voit liad conducted upon the dog, and among them are two 

 series of observations which illustrate the subject at present 

 under consideration. 



In the first no food at all was given, and the patients were 

 kept at rest. 



In one ca?;e 8 grms. of nitrogen were passed, in a second 10, 

 and in a third S'6. In a fourth case the amount was as low as 

 6. And in another series of observations upon himself, Ranke 

 found the amount passed in two starvation days to be 8 and 8'5 



prisoner.--, and found as the mean of three days S'6 grms. 



Many other observers have noticed the rapid fall in the 

 amount of nitrogen excreted during starvation. 



But the short duration of these experiments makes it probable 

 that the minimum was^not reached. 



We have then 8 gruis. as the mean of the only reliable deter- 

 mination at our command of£the nitrogen excreted in the urine 

 daring starvation. 



Frof. Playfair attacked the question from another side, by 

 collecting from various sources the minimum diets upon which 

 man could live, and to which he gave the name of subsistence 

 diets, and by calculation the amount of nitrogen contained in 

 them. This method gave him as a mean 9 2 grms., but his 

 patients were none of them at absolute rest,'_but were perform- 

 ing during the day a certain amount of work. Edward Smith 

 in the same way, by calcula'ion from the diets of the spinners 

 during the cotton famine, found a somewhat larger amount of 

 nitrogen (12 grms.), \\hich agrees with the amount of nitrogen 

 contained in Playfair 's second class of small diets, but in all 

 these cases the effect of muscular exertion is not eliminated. 



Unruh gives a series of three observations upon hospital 

 patients kept at rest and placed upon a restricted diet. 



In the first, a case of cancerous obstniction, the amount of 

 nitrogen was 8 grms. (i7"5 urea). But this case is not altogether 

 satisfactory, from the amount of wasting accompanying this 

 disease. ; 



The other two were cases of syphilis placed upon fever diet, 

 and kept at rest for the sake of the experiments ; the first passed 

 8'6 grms. (iS'6 urea), the second 7'5 grms. (i6'2 urea). 



The mean of these three cases is S grms. (I7"S urea). 



The general results of the various series of observations may 

 be roughly tabulated thus : — 



I. Starvation. 8 gi'ms. 



II. Non-nitrogenous food. 8 grms. 



III. Subsistence diet. 9 grms. 



IV. Insufficient diet. 8 grms. 



V. Clinical equilibrium. 8 grms. 



A remarkable coincidence, considering the variety of the 

 methods employed and the different conditions under which the 

 determinations were made. 



We may therefore conclude that the minimum amount of 

 nitrogen excreted by a healthy adult man is on the average 8 

 grms. in the twenty-four hours, this being equivalent to I7"S 

 8;rms., or to 260 grains of urea. 



Geological Society, June 9. — Robert Etheridge, F.R.S., 

 president, in the chair. — John Bum Anstis du Sautoy and Rev. 

 John Cowley Fowler, B.A., were elected Fellows ; Prof. G. 

 Dewalquf, Liege, a Foreign Member, and Prof. Leo Lesquereux, 

 Columbus, U.S., a Foreign Correspondent of the Society. — 

 The following communications were read : — On the occurrence 

 of marine shells of existing species at different heights above the 

 present level of the sea, by J. Gwyn Jeffreys, F.R.S., Treas. 

 G.S. This paper resulted from the author's examination of the 

 moUusca procured during the expeditions of H.M.SS. Li^/iliiing 

 and Porcupine in the North Atlantic. He stated that he found 

 several species of shells living only at depths of not less than 

 between 9,000 and 10,000 feet, which species occurred in a fossil 

 state in Calabria and Sicily at heights of more than 2,000 feet, such 

 depths and heights together exceeding the height of Mount Etna 

 above the present level of the Mediterranean. He then gave an 

 account of the post-tertiary deposits in Europe, Asia, and North 

 America, to show their various height-, and especially of the 

 raised beach on Moel Tryfaen in Caernarvon-hire, which was 

 from 1,170 to 1,350 feet high. Some of the shells in that 

 deposit were boreal, and did not now live in the adjacent sea. 

 The author stated that no shells of a peculiarly northern charac- 

 ter had been noticed in the west or south of England. He then 

 questioned the permanence and even the antiquity of the present 

 oceanic basins, from a consideration not only of the fauna which 



now inhabits the greatest depths, but also of the extent of oscil- 

 lation which had prevailed everywhere since the Tertiary period. 

 A complete list of the Moel Tryfaen fossils was given, to the 

 number of sixty, besides three distinct varieties, of which num- 

 ber eleven w ere Arctic or northern, and the rest lived in Caer- 

 narvon Bay. All of these fossils were more or less fragmentary. 

 — On the pre-Devonian rocks of Bohemia, by J. E. Marr, B.A., 

 F.G.S. The author commenced nith a brief notice of the pre- 

 Cambrian rocks, which are gneisses and schistose limestone with 

 intrusive eclogite ; over these lie unconformably green grits, 

 ashes, breccias, hornstones (etage A of Earrande), which the 

 author considers to represent the Harlech group of Wales. 

 Etage B is unconformable with this, but conformable with C, 

 which contains the "primordial" fauna. D contains the colo- 

 nies. E to H are Silurian, and more calcareous than these 

 underlying them. The base of the group is unconformable with 

 those beneath. The lithological characters of the various beds 

 were described. The following are the associated igneous 

 rocks : — Granite, quartz feltzite, porphyrite, mica-trap, diabase, 

 diorite, eclogite. Of these brief descriptions were given. The 

 author gave a comparison of the various shales with English 

 deposits. The pre-Cambrian series much resemble the Dimetian 

 and Pebidian of Wales, the latter being etage A ; etage B, the 

 Harlech ; etage C, the Menevian, probably a deep-water de- 

 posit, as is indicated by the abnormal size of the eyes of its 

 Trilobites ; the lowest bed of etage D probably represents part 

 of the Lingula flags of Britain. D, a, i, B, seems to represent 

 the Tremadoc shale of Britain, and, like it, contains pisolitic 

 iron-ore. Representatives also of the Arenig and Bala beds ar 

 found. A slight unconformity marks the base of the Silurian^ 

 Three graptolitic zones occur. The lowest, or Diplograptus. 

 zone, identical with the Birkhill shales, contains thirteen species 

 of graptolites ; the next, or Priodon zone (four species) re- 

 sembles the Brathay llags ; the upper, or Colonics zone (five 

 species), resembling the Upper Coldwell beds of the Lake- 

 district. Above these follow representatives of ^Venlock, 

 Ludlow, and probably of the Passage beds. The author, with 

 the evidence of these, discussed the " colonies " theory of M. 

 Barrande, pointing to the non-intermixture of species, notwith- 

 standing the irregular repetition of the zones, the non-occurrence 

 of the.-e colony species in intermediate beds, and other reasons. 

 The stratigraphy and palaeontology of several of these colonies 

 were discussed in detail, showing it to be more probable that 

 their apparent intercalation with latter faunas is due to repetition 

 by faulting. — On the pre-Cambrian rocks of the North-Westeru 

 and Central Highlands of Scotland, by Henry Hicks, ^LD., 

 F.G.S. The author, after examination, considers the rocks of 

 the following districts to be wholly or in part pre Cambrian : — 

 (l) G!cn Finnan, Loch Shid to Caledonian Cana! ; (2) fort 

 William and Glen Nevis ; (3) Balladnilish, Glen Coe, and Black 

 Mount ; (4) Tyitdrum to Callander. The author states that the 

 Silurian (and Cambrian) rocks flank the pre-Cambrian in lines 

 from north east to south-west, and overlap Ben Ledi on the 

 south side. Thus here, as elsewhere, subsequent denudation 

 has removed enormous masses of the more recent rocks, only 

 here and there leaving patches of these in folds along depressions 

 in the old pre-Cambrian floor. 



Edinburgh 

 Royal Society, May 17. — Mr. D. Milne Home, vice-presi- 

 dent, in the chair. — Mr. J. B. Haycraft, M.B., B.Sc, read a 

 paper on a meth id for the quantitative estimation of urea in the 

 blood. The method depended upon the fact that one cm 

 dialyse the fluid parts of blood into alcohol, into which the urea 

 passes in a very pure form. The alcohol containing the ures 

 is evaporated, the residue washed with petroleum ether, re 

 extracted, and estimated after the method of Huefuer. This 

 method yields urea from so small a quantity of blood as 10 cc, 

 and shows that more is present than was formerly conjectured, 

 there being on an average 35 parts per 100,000. — Mr. Patrick 

 Geddes, in his paper on the phenomena of variegation and cell- 

 multiplication in a species of Enteromorpha, pointed out that 

 the development of colourless cells in this alga was by a process 

 of budding into the intercellular spaces between the coloured 

 cells, so that both kinds of cell-multiplication, by fission and by 

 budding, were exemplified in the same plant. — Prof. Tait gave a 

 communication on the accurate measurement of high pressures. 

 For pressures up to a few tons the behaviour of nitrogen had 

 been thoroughly investigated (at least at one temperature). By 

 comparison with a nitrogen compression gauge, a scale could be 



