472 



NATURE 



ySept. 30, 1875 



principles, both phosphorised and nitrogenised. Among 

 the phosphorised, [kephalin and myehn (both of which 

 contain nitrogen, as well as phosphorus) are new, and are 

 associated with lecithin. They are described as typical 

 colloids, of no true solubility, of almost indefinite power 

 of soaking up water so as'to form an imperfect solution^ 

 of feeble chemical activity, of a remarkable readiness to 

 combine with acids salts and alkalies, and to part with 

 them on the addition of excess of water. Kephalin and 

 myelin are stable, lecithin so unstable as to elude proper 

 analysis. Similarly the nitrogenised bodies, cerebrine 

 (Miiller's), kerasine, and phrenosine, are colloids, but of 

 less perfectly marked type, and less interesting natural 

 history. 



In his summary Dr. Thudichum, speaking of the phos- 

 phorised bodies, remarks that " we have therefore here a 

 diversity of affinities such as is not possessed by any 

 other class of chemical compounds- in nature at present 

 known ; and the exercise of these affinities being greatly 

 influenced by the mass of reagent and the mass of water 

 which may be present, the interchange of affinities may 

 produce a perfectly incalculable number of states of the 

 phosphorised and consequently of brain matter. This 

 power of answering to any qualitative and quantitative 

 influence by reciprocal quality or quantity we may term 

 the state of labile equilibrium j it foreshadows on the 

 chemical side the remarkable properties which nerve 

 matter exhibits in regard of its vital functions." 



The volume now under consideration has been pre- 

 ceded by two volumes, containing a first and second 

 report by Dr. Klein, on the Lymphatic System and its 

 relation to Tubercle, a report by Dr. Sanderson on the 

 Infective Products of Inflammation, and by Dr. Thu- 

 dichum on Chemical Changes in cases of Typhus. Re- 

 ports are now in course of preparation by Dr. Baxter on 

 Disinfectants, by Dr. Sanderson on the Febrile Process 

 and on Infective Inflammations, by Dr. Thudichum on 

 the Chemical.Constitution of the Brain, by Dr. Creighton 

 on Anatomical Studies with reference to Cancer, by Dr. 

 Klein on the Contagium of Enteric Fever. The whole 

 represents four years' work, for which 8,000/. has been 

 voted. The value' and importance of all this work in 

 relation to the welfare of the community, as a contri- 

 bution in aid of preventive medicine, cannot be doubted 

 by any careful reader of the record. Nor, after even a 

 superficial reading of the record can there be doubt but 

 that the work is of a kind which can only be set going by 

 such means as public grants, since it involves a special 

 training and a special devotion inconsistent with the 

 earning of livelihood by other direct or incidental means. 

 The grant is on the evidence justified. 



But there are other aspects of the work which claim 

 a serious regard. The department of the Government 

 concerned in protecting the country from the invasions of 

 contagious disease, whether represented by Minister of 

 .Health or principal medical officer, needs'in all things to 

 be fully informed of the latest discoveries in pathology, 

 hygiene, and therapeutics. Of such minister or officer 

 the body of scientific [men whose work is here recorded, 

 together with others who are engaged in sanitary inves- 

 tigations and inspections under the central authority — 

 men hke Drs. Seaton and Buchanan and Mr. J. N. Radcliffe 

 — constitute a body of advisers or council representing the 



most advanced knowledge bearing upon the public health. 

 They constitute a council to which the minister or officer 

 may refer for latest knowledge when legislation is con- 

 cerned, or for practical advice when action has to be 

 taken. They are, in fact, at this moment practically 

 such a council. In the Science Commission Report on 

 the Advancement of Science, the formation of a similar 

 council as adviser of a Minister of Science is advocated. 

 We would suggest that we have in what we have stated 

 an excellent illustration of the| principle proposed, with a 

 wider application, in the Science Commission Report. 



THE INFLUENCE OF THE PRESSURE OF 



THE ATMOSPHERE ON HUMAN LIFE 



Injluence de la pression de I'air sur la vie de Vhomiiie. 



Par D. Jourdanet. 2 vols. (Paris : Masson, 1874.) 



AFTER having practised medicine Tor six years on 

 the borders of the Gulf of Mexico, and rendered 

 himself familiar with the diseases and conditions of life of 

 the inhabitants of low levels, M. Jourdanet removed to 

 the elevated plateau of Anahuac — more than 2,000 metres 

 above the sea level. Here, as might have been antici- 

 pated, he found the pathological conditions different, but 

 to his surprise he discovered that the differences were not 

 simply such as result from temperature, or are paralleled 

 in places of lower level and higher latitude, but presented 

 pecuharities which he conceived to be dependent on the 

 elevation of the situation alone. A residence of twenty 

 years in the locality enabled him to confirm this idea 

 and to prove that, while the blood of the inhabitants pre- 

 sented no poverty of corpuscles, the corpuscles themselves 

 were deficient in oxygen, on account, as he believed, of 

 the too feeble pressure of the atmosphere in these high 

 regions. This led him to undertake the study of the 

 whole question of the influence of the atmospheric pres- 

 sure on health, and to call to his aid M. Paul Bert, 

 Pi-ofessor of Physiology at the Sorbonne, by means of 

 whose experiments he believes himself to have arrived at 

 some definite results. These, with every other possible 

 point of interest connected with the subject, he now 

 presents us with, in two large and beautifully illustrated 

 volumes ; leaving, however, the details of the physio- 

 logical experiments to be pubHshed in a forthcoming work 

 by M. Bert himself. 



The question so fully discussed by M. Jourdanet is 

 certainly of very great interest, and, in spite of previous 

 observations and opinions on the therapeutic action of com- 

 pressed air and on the possible limits of life in regard to 

 height and other similar points, it is also of some novelty 

 as treated by him. 



According to M. Jourdanet the pressure of the atmo- 

 sphere has not always been as small as it is now ; and 

 assuming, what is probably true, that a greater pressure 

 would involve greater heat, he would account in this way 

 for the warm periods known to have existed in Tertiary 

 times. This leads him to make an hypothesis as regards 

 the cause of the glacial epoch, the occurrence of which 

 would be contrary to the above theory ; but it is not an 

 hypothesis that could recommend itself to geologists. 

 The glacial epoch arose, he imagines, in this way ; by 

 some sudden convulsions the crust of the earth was torn 

 open, and prodigious quantities of gas and vapour driven 



