46 



NA TURE 



[May 14, 190S 



of amorphous carbon takes place through the agency of 

 bacteria. This has been conclusively established by experi- 

 ments upon such carbonaceous substances as charcoal, 

 lamp-black, coal, and peat. 



When these substances are subjected to bacterial action 

 carbonic acid is given off, as estimated volumetrically by 

 absorption in baryta solution and titration with standard 

 oxalic and hydrochloric acids. 



The amount of CO, given off increases in proportion to 

 the rise of temperature, and ceases to be evolved at a 

 supra-vital temperature. There is no evolution of CO, 

 under perfectly dry conditions such as preclude the possi- 

 bility of bacterial liTp. " , 



\ distinct rise of ten ^;rature occurs through the action 

 of bacteria. The hea^ generated was determined by 

 measurement, with a galvanometer, of the electromotive 

 force produced by the difference of temperature between 

 two thermo-clements, one placed in a sterile and the other 

 in an inoculated flask. 



The evolution of CO, and the accompanying rise of 

 temperature does not take place when carbonaceous sub- 

 stances are preserved from the intrusion of niicro- 

 org.-:nisms. 



The heat generated by microbial activity is an influence 

 to be taken into account in connection with the oxidation 

 and spontaneous combustion of coal; it may be a dangerous 

 motive force acting upon explosive gases. 



The oxidising action of bacteria must be largely re- 

 sponsible for the disintegration of coal and the high 

 percentage of depreciation which it undergoes in store. 



Coal and peat, like other organic matter, are liable to 

 decomposition as soon as conditions are presented suitable 

 for the life of aerobic organisms. The carbon is then once 

 more liberated in the form of CO, to plav its rule in the 

 life-cycle. It is thus conceivable that the 'vast supplies of 

 carbon locked up in the world's coalfields mav become 

 available for plant nutrition without the intervention of 

 direct combustion, 



"The Origin and Destinv of Cholesterol in the Animal 

 Organism," parts i. and ii. Bv C. Dor^e and J. A. 

 Gardner. Communicated by Dr. A. D. Waller, F.R.S. 



These two papers throw some further light on the 

 interesting question of the part plaved by cholesterol 

 in the economy. The authors made, first, a very thorough 

 and careful examlnalion of the excretion of cholesterol by 

 the dog. The animal was fed for periods varying betwieii 

 fourteen and thirty days on diets the cholesterol content 

 of which varied greatly. The output of cholesterol in 

 the fa;ces was in every case found to be a function of 

 the food taken. Thus in seventeen davs on horseflesh 

 one gram of cholesterol was recovered, in thirtv-one days 

 on oatmeal and water o-i gram only. On a diet of ra\v 

 brain, which is rich in cholesterol, a very interesting 

 result was observed. In fourteen davs ' the outpu't 

 amounted to 17 grams, and it consisted entirely of 

 eoprosterol, the dihydrocholesterol normally presen't in 

 human fa?ces. In every experiment the cholesterol actuallv 

 found was very much less than the quantitv that .should 

 have been poured into the intestine with 'the bile. 



In the excrement of grass-fed anim,-iU the main cholesterol 

 product is the so-called hippocoprosterol, which is shown 

 to be an alcohol, C,.Hj,0, melting at 70° C. But far 

 Irom being, as previously supposed, reduced from cholesterol 

 m the mtesline of the animal, it is merely a constituent 

 of the grass taken as food. This was tin.-illv and clearlv 

 proved by feeding a rabbit on grass from which the 

 chortosterol (as the authors propose to re-name it) had 

 been removed liv extractln., with ether. The bodv could no 

 longer be obtained from the f.-eces. No trace of cholesterol 

 was found in the excrement of the herbivora examined, and 

 It thus appears probable that the cholesterol of their bile 

 IS actu.iUv absorbed in the intestine — a point at present 

 under investigation. 



April 2. — " The Antagonistic Action of Calcium upon 

 the Inhibitory Effect of Magnesium." By S. J. Meltzer 

 and J. Auer. Communicated by Prof. 'K. H Starlin" 

 F.R.S. ■ '" 



In a series of recent studies which the authors h.ive 

 carried out upon the relations of the effects of calcium to 

 magnesium, many facts came to light which demonsirati- 



NO. 201 I, VOL. 78] 



unmistakably that calcium is the most available agent to 

 neutralise inhibitory effects of magnesium. The follow- 

 ing experiment is an instance : — 



By subcutaneous injections of a magnesium salt (for 

 instance, Epsom salt — about 7 c.c. of a "25 per cent, solu- 

 tion per kilogram), rabbits are brought to a profound stale 

 of anaethesia and paralysis. The slow and sliallow re- 

 spirations indicate the approaching danger. Now 6 c.c. 

 or S c.c. of an M/6 or an M/8 solution of a calcium salt 

 are given through the ear vein. Within a few seconds 

 the respiration becomes quicker and deeper, and within 

 one minute the animal turns over, sits up, and appears 

 normal. 



Here calcium not only did not add an inhibitory effect, 

 but completely neutralised the profound inhibitory effect 

 of magnesium. The companionship of calcium and mag- 

 nesium within the body means, at least in many instances, 

 not a concerted action of similar effects, but rather .1 

 resultant cltect of antagonistic actions. 



Royal Microscopical Society, April 15. — Mr. Coorad 

 Beck, vice-prrsident, in the chair. — Dendritic growths of 

 oxide of copper on paper : J. Strachan. The results 

 verified previous investigations, showing that these 

 dendrites originated in minute particles of copper, their 

 branching being due to the direction of the fibres in the 

 paper. — Nature's protection of insect life : F. Enock. The 

 slides were taken by the Sanger-Shepherd three-colour 

 process, and Mr. Enock described the method he employed 

 In their production. 



Geological Society, April 15.— Dr. J. J. Harris Teall, 

 F.R.S., vice-president, in the chair. — The geological struc- 

 ture of the St. David's area (Pembrokeshire) : J. F. N. 

 Green. The Cambrian rocks were first traced and found 

 to be faulted greatly. The faults have been followed into 

 the volcanic tufts (Pebidian), and the succession determined 

 and pieced together. In this way the Pebidian has been 

 subdivided into fourteen horizons, with a total visible 

 thickness of more than 3000 feet. The subdivisions are 

 classified into four series, the lower two of which are 

 composed of trachytic pebbles in a chloritic matrix, and 

 separated by a schistose quartz-felspar-porphyry sill. The 

 third series is composed of rhyolite and hidleflinta frag- 

 ments in a silicified matrix, and the topmost of highly 

 sheared schistose beds. The tuffs appear to be mainly 

 detrital. ;\n unconformity between the Pebidian and the 

 Cambrian is demonstrated. The schistose sill has been 

 traced into the porphyrilic margin of the .St. David's grano- 

 phyre (Dimetlan), and it is inferred that the granophyre 

 is a laccolitic intrusion in the Pebidian. The boundaries 

 between the granophyre and the Cambrian are prolonga- 

 tions of faults proved in the latter, except at one point in 

 the well-known Porthclais district. A trench opened here 

 exposed basal Cambrian rocks resting upon a denuded 

 surface of the granophyre, which is therefore of pre- 

 Cambrian, but of post-Pebidlan age. The relationships of 

 the basic igneous rocks west of St. David's are discussed, 

 and they are all described as post-Cambri.an intrusions. — 

 Notes on the geology of Burma : L. \'. Dalton. Thi' 

 results are given of geological expeditions in the IrawadI 

 X'aliey, carried out between 1904 and iQoh, and present 

 knowledge of the geology of Burma in general and of 

 the Tertiary system in particular is summarised. 



Zoological Society, April 28. — Dr. Henry Woodward, 

 F.R.S., vice-president, in the chair. — .\ revision of th'- 

 sharks of the family Orectolobid* : C. Tate Regran. 

 Twenty-one species were described, and were referred to 

 eight genera. Attention was directed to the great differ- 

 ences in form, coloration, &c., among the members of the 

 family, corresponding to differences in habits and environ- 

 ment. — Identification of an oligoch;ctc worm obtained in 

 considerable numbers from a well near Cambridge, 

 England : F. E. Beddard. The author described the 

 worm as a new specli's of the genus Phreatothrix, the 

 only other species of which had been described thirty years 

 ago from the underground waters of Prague. — The 

 amphiix)d genus Trischizostoma : Mrs. E. W. Sexton. 

 The memoir was based on a rich material obtained by 

 the ste.imer of the Marine Biological .V^sdciation in the 

 Bay of Biscay, and bv the steamer of ihi' Irish Depart- 

 ment of Agriculture off the west coast of Ireland. — Certain 



