November 24, 1910] 



NATURE 



127 



ii 



proteolytic enzyme of drosera. — L. S. Dudgreon, P. N. 

 Panton, and H. A. F. Wilson : The influence of bacterial 

 endotoxins on phagocytosis (including a new method for 

 the 'differentiation of bacteria). Second report. The 

 authors have failed to demonstrate in any of their experi- 

 ments an action of the endotoxic substances on the leuco- 

 cytes, and experiments leading to similar results were 

 obtained by allowing bacteria to be exposed to the action 

 of the specific endotoxic substances. They confirm the 

 results published in the first communication, that the 

 phagocytic result is dependent upon the interaction of 

 endotoxin of serum. They have shown in the case of 

 normal serum that the amount of phagocytosis permitted 

 when bacteria and endotoxin interact is not related to the 

 amount of haemolytic complement present. The action of 

 endotoxin appears to be specific even with bacteria so 

 closely related as the typhoid and paratyphoid family. 

 These results strongly suggest that this method can be 

 employed for the differentiation of bacteria. The amount 

 of endotoxin has been shown to be strongly thermo- 

 stable. — S. B. Schryver : Some investigations on the 

 state of aggregation of matter. Parts I. -III. Fart I. 

 The action of salts in heterogeneous systems and the 

 nature of the globulins. — When complex substances, such 

 as those which form colloidal solutions, enter into chemical 

 reaction, the ordinary laws of chemical mass action are 

 not always obeyed, the deviations therefrom depending 

 upon the medium in which the reaction takes place. 

 These are due' to the adsorption of molecules from the 

 medium on the surface of the large molecules of the 

 colloid, which sterically inhibit chemical reaction. These 

 conclusions were deduced chiefly by the study of the action 

 of formaldeh3'de on Witte's peptone, whereby a methylene- 

 imino derivative is formed, which readily, either by poly- 

 merisation or condensation between two molecules, forms 

 an insoluble complex. The formation of this complex is 



hibited by the presence of salts, the inhibitory action of 

 . series of which has been quantitatively measured. The 

 degree of inhifcition was found to depend, in the case of 

 monobasic sodium salts, on the physical properties of their 

 aqueous solutions. The lower the surface tension and the 

 lower the viscosity of the solutions, the greater the 

 Inhibitory action. The effect of surface tension could be 

 deduced from the general study of adsorption phenomena, 

 whilst the effect of viscosity could be deduced by the 

 extension of the generalisations of Whitney and Noyes, 

 and of Xernst as to the reaction rates in heterogeneous 

 systems. The globulins, which are insoluble in water but 

 soluble in salt solutions, are assumed to be complexes 

 formed by the action of a basic group in one molecule 

 with an acid group in another, by means of which a salt 

 is formed, which undergoes slight but definite hydrolytic 

 dissociation in the presence of water. In the presence of 

 most salts, owing to adsorption by the dissociated globulin 

 molecules, hydrolysis proceeds further than in presence of 

 water alone, with the consequence that more globulin is 

 dissociated and "dissolved." The solvent action of the 

 salts here again depends upon the surface tensions of the 

 solutions. Salts exert also a similar action in other 

 heterogeneous systems in bringing about disaggregation, 

 and the differences of solubility of various crystalline sub- 

 stances in salt solutions can be thereby explained. The 



hysical constants of the salt solutions employed, and the 

 -olubilities of edestin and serum globulin in these solu- 

 tions, are given. Part II. The action of formaldehyde 

 on Witte's peptone. — The experimental details of this 

 investigation are given. It is shown that the insoluble 

 precipitate, formed by the interaction of the solutions, is 

 derived chiefly from the more complex polypeptides. 

 Part III. The solubility of phenol and certain crystal- 

 line substances in salt solutions.— The deductions as to the 

 action of salts in heterogeneous systems are illustrated by 

 the determination of the critical solution temperatures of 

 phenol and salt solutions, which is a function chiefly of 

 the surface tensions of the latter, and of the solubilitv 

 of 'the following substances in salt solutions: — d-Weucine, 

 d-Z-phenylalanine, caffeine, benzamide, and />-toluidine. 

 The solubilities are affected by both the surface tensions 

 and viscosities of the solutions. — F. W. Twort : A method 

 for isolating and growing the lepra bacillus of man. 

 Experiments were undertaken to obtain a method whereby 

 the lepra bacillus of man and allied bacilli might be 



NO. 2143, VOL. 85] 



cultivated ' outside the body on artificial media. The 

 material tested was obtained from a typical leper. Culti- 

 vations were made on ordinary laboratory media and on 

 media containing extracts from animal organs and tissues ; 

 these gave negative results. In view of the close relation- 

 ship between the tubercle bacillus and the lepra bacillus, 

 it appeared highly probable that these two micro-organisms 

 would require the same chemical substances for building 

 up ■ their protoplasm which could be elaborated from the 

 ordinary media only by the- tubercle bacillus. It was 

 thought that if these substances could be supplied already 

 formed to the lepra bacillus it might grow, and the easiest 

 method of supplying these substances would be by adding 

 to some good medium the ground-up bodies of the tubercle 

 bacilli containing them ; accordingly a medium was made 

 as follows : — egg three parts, o-8 per cent, sodium chloride 

 one part, ground tubercle bacilli i per cent., and glycerine 

 5 per cent, or less, mixed, placed in tubes, sterilised, and 

 set in slopes. Leprosy material was placed in 2 per cent, 

 ericolin to kill contaminating micro-organisms, and then 

 inoculated on the tubercle medium. On this the lepra 

 bacillus grew very slowly as a delicate, colourless streak 

 along the inoculated track, and showed the typical morpho- 

 logical and staining characters of the lepra bacillus ; the 

 bacillus could be sub-cultured only on the tubercle 

 medium. Experiments will be made to prepare a lepra 

 vaccine and to grow the lepra bacillus of rat. In con- 

 junction with Mr. Ingram, the author has also succeeded 

 in growing the bacillus found in Johne's disease of cows. 

 It grows on the same medium, much like lepra bacillus, 

 but somewhat faster. It is hoped soon to prepare a 

 diagnostic vaccine for Johne's disease. — G. J. Fowler, 

 E. Ardern, and W. T. Lockett : The oxidation of phenol 

 by certain bacteria in pure culture. The investigation 

 described in the paper arose out of a detailed examination 

 of the effect of various antiseptic substances, including 

 phenol, in bacterial sewage filters. It was found that the 

 phenol apparently exerted a selective action on the 

 bacteria present in the filter, only very few types 

 appearing in the filtrate, more especially a liquefying 

 organism (B. liquefaciens fluorescens) and a chromogenic 

 organism. Pure cultures of these organisms were made, 

 the medium generally used being ordinary peptone broUi. 

 The general method of experiment was - to bubble air, 

 under sterile conditions, through an aqueous solution of 

 phenol to which a few c.c. of the culture were added. 

 The strengths of phenol solution used varied from 8-4 to 

 16-5 parts phenol per 100,000 of water, and were deter- 

 mined by the oxygen absorbed from standard acid per- 

 manganate solution in three minutes. It was found that 

 B. liquefaciens had no action, or only a very slight one, 

 on phenol, even after exposure of a month or more, while 

 on introduction of the chromogenic organism the phenol 

 content diminished, slowly at first, and then, in two or 

 three days, completely disappeared. In a final experi- 

 ment, a solution was made use of containing 10 parts 

 per 100,000 of phenol, together with the following in- 

 gredients : — 



Ammonium sulphate o*i grm."| 



Potassium phosphate O"! ,, Ip^ ^ y^^p^ 



Magnesium carbonate ... ^-I ,, j '^ 

 in suspension. j 



.After careful sterilisation this was inoculated with the 

 organism, and incubated. After nine days the phenol had 

 practically disapf>eared. Plate cultures were also made at 

 the expiration ol this time, and showed no evidence of 

 the presence of more than one species of organism. The 

 organism has been examined by Dr. Sidebotham, who 

 concludes that it most nearly resembles B. helvoTus 

 (Zimmermann). 



Mineralogical Society, November 15.— Prof. W.J. Lewis, 

 F.R.S., president, in the chair. — J. H. Collins: Further 

 notes on wood-tin. It is concluded that wood-tin, which 

 always contains a good deal of iron oxkie, and is much 

 more opaque and more soluble than ordinary cassiterite, 

 is the chalcedonic form, the shot-tin having had a con- 

 cretionarv, and the botryoidal form a stalagmatic, origin. 

 — J. M. Coon : The alteration of the felspar of granites 

 to china-clay. The action has taken place from within the 

 earth towards the surface below the underground water- 



