October 22, 1903] 



NATURE 



609 



respect to actively functionating and intact cells. It is 

 obvious, therefore, that the first desideratum is a suitable 

 method of obtaining the cell plasma for experimental pur- 

 poses, and it is only recently that this has been successfully 

 accomplished. The most feasible means of procedure 

 appeared, to be the use of mechanical agents which, whilst 

 bringing the cell substance within the field of observation, 

 would, at the same time, be least likely to affect its 

 character and constitution. The method consists in a 

 mechanical rupture of the cells and the release of their 

 contents under conditions favouring the conservation of 

 their properties. The first successful application of this 

 description of method was made by Buchner in the par- 

 ticular instance of the yeast cell, and with brilliant results. 

 The researches of Buchner were of wide biological signifi- 

 cance, and were suggestive of much more than a cell-free 

 alcoholic fermentation of sugars. They demonstrated the 

 possibilities of the new methods with regard to more general 

 vital problems. The Buchner process consisted in a 

 mechanical trituration of the yeast cell with the aid of sand 

 and a subsequent filtration of the resultant mass under 

 pressure through Kieselguhr. The filtrate contained the 

 expressed constituents of the yeast cell which were capable 

 of passing through Kieselguhr, and the product, in virtue 

 of its fermentative properties, was termed " zymase." 



The author and his colleagues have, during the past 

 four years, been engaged in investigating the application 

 of cognate methods to biological research. The advice and 

 help generously afforded by Prof. James Dewar materially 

 forwarded the progress of the research. 



It was considered that, by the employment of low 

 temperatures, a disintegration of living cells might possibly 

 be accomplished, and a wide field of inquiry opened to in- 

 vestigation in the biological laboratory. For this purpose 

 the methods of mechanical trituration required refinement 

 in several directions. 



The conditions it was desired to fulfil were, a rapid dis- 

 integration of the fresh tissues and cells, an avoidance of 

 heat and other modifying agents during the process, and 

 an immediate manipulation of the cellular juices obtained. 



It had likewise been noted that ordinary filter pressing 

 through Kieselguhr removed physiologically active sub- 

 stances from the cell juices. Liquid air appeared to be the 

 most convenient means of obtaining the necessary cold, and it 

 presented the advantage of a fluid freezing medium in which 

 the material to be manipulated could be directly immersed. 

 The temperature of this reagent (about — 190° C.) would, in 

 addition, prevent heat and chemical changes,, whilst re- 

 ducing the cells to a condition of brittleness favourable to 

 their trituration without the addition of such substances as 

 sand and Kieselguhr, which might modify the composition 

 of the resultant prodiict. 



The method, if successful, would meet the conditions 

 desired for the subsequent study of the intracellular juices. 

 It may be briefly and generally stated that, by the appli- 

 cation of low temperatures, a mechanical trituration of 

 every variety of cell per se has been accomplished, and the 

 fresh cell plasma obtained for the purpose of experiment. 

 A number of control experiments have demonstrated that 

 immersion in liquid air is not necessarily injurious to life — 

 bacteria, for example, having survived a continuous ex- 

 posure for six months to its influence. The actual tritura- 

 tion of the material is accomplished in a specially devised 

 apparatus, which is kept immersed during the operation in 

 liquid air. 



The normal and diseased animal tissues have been treated 

 in this manner, and their intracellular constituents obtained, 

 (■.,47. epithelium, cancer tissues, &c. 



Moulds, yeasts and bacteria have been rapidly triturated 

 under the same conditions, and the respective cell juices 

 submitted to examination. 



The severest test of the capabilities of the method was 

 furnished by the bacteria, an order of cells for which the 

 standard of measurement is the mikron. The experiments 

 proved successful in every instance tested. The typhoid 

 bacillus, for example, is triturated in the short space of 

 two to three hours, and the demonstration has been fur- 

 nished that the typhoid organism contains within itself a 

 toxin. From these and other researches it has become 

 evident that there exists a distinct class of toxins and fer- 

 ments which are contained and operate within the cell or 

 bacterium, in contradistinction to the now well-known class 



of toxins which are extracellular, i.e. extruded during life 

 from the cell into the surrounding medium. To this latter 

 class belongs the diphtheria toxin, which has been so 

 successfully used in the preparation of diphtheria antitoxin. 

 A number of infective organisms do not produce appreciable 

 extracellular toxins, and the search must therefore be made 

 within the specific cells for the missing toxins to which 

 the intoxication of the body in the course of the disease in 

 question is probably due. The practical utility of investi- 

 gating these intracellular toxins has already become 

 evident in the preparation from the intracellular toxin of 

 the typhoid bacillus of a serum having antitoxic value as 

 regards this toxin. 



The experiments made with the pus organisms have 

 already shown that intracellular toxins exist in this im- 

 portant order of disease germs. 



The cell juices of other types of pathogenic bacteria, such 

 as the tubercle and diphtheria bacillus, present character- 

 istics of equal interest. 



The application of low temperatures has aided the investi- 

 gation of certain other biological problems. 



The photogenic bacteria preserve their normal luminous 

 properties after exposure to the temperature of liquid air. 

 The effect, however, of a trituration at the same tempera- 

 ture is to abolish the luminosity of the cells in question. 

 This points to the luminosity being essentially a function 

 of the living cell, and dependent for its production on the 

 intact organisation of the cell. 



The rabies- virus has not yet been detected or isolated, 

 although regarded as an organised entity. The seat of the 

 unknown rabies virus is the nervous system. If the brain 

 substance of a rabid animal be triturated for a given length 

 of time at the temperature of liquid air, its infective proper- 

 ties as regards rabies are abolished. This result appears 

 to be a further indication of the existence in rabies of an 

 organised virus. 



The method described admits of a fresh study of the 

 question of immunity from an intracellular standpoint. 



The intracellular juices of the white blood cells have been 

 obtained, and tested with regard to bacteriolytic properties 

 and the natural protection that may thus be afforded to the 

 bodv against the invasions of microparasites. 



The application of low temperatures to the study of bio- 

 logical problems has furnished a new and fruitful method 

 of inquiry. 



PHYSICS AT THE BRITISH ASSOCIATION. 



THE meeting of the International Meteorological Com- 

 mittee at Southport during the week of the meeting 

 of the Association resulted in an unusually large proportion 

 of the papers presented to Section A dealing with cosmical 

 problems, and these were taken in the department of 

 the section devoted to astronomy and meteorology. Of the 

 matters brought before the department devoted to physics, 

 there seems little doubt that the most important were 

 those involved in the discussions on the introduction of 

 vectorial methods into physics, on the treatment of 

 irreversible processes in thermodynamics, and on the nature 

 of the emanations from radio-active substances respectively, 

 and of these a short account follows. 



In opening the discussion on the introduction of vectorial 

 methods into physics. Prof. Henrici pointed out that, 

 although vectors were invented for use in dynamics, the 

 ideas involved were fully introduced into physics by 

 Faraday's representation of the stresses in a medium by 

 lines of force. Maxwell was aware of this, and devoted 

 some sections of the opening chapter of his " Electricity 

 and Magnetism " to an exposition of the properties of 

 vectors, and expressed many of his later equations in 

 vectorial form. 



So long as we have to deal with quantities which 

 involve magnitude and direction, but which are not 

 specified as starting from a definite point, i.e. with non- 

 localised vectors, a very simple algebra is all that is 

 necessary, and when at any time it is required to extend 

 our methods to localised vectors the methods of Grassmann's 

 " Ausdehnungslehre " are available. The algebras which 

 have been proposed for dealing with the simpler case agree 

 in making addition follow the parallelogram law for com- 

 pounding two forces, but they differ in the meanings they 



NO. 1773. VOL. 68] 



