Febbuart 9, 1906.] 



SCIENCE. 



219 



pension in all of our experiments. The 

 clinical bearing- of these experiments is in- 

 dicated by the fact that those individuals 

 whose phagocytic index was lowest had 

 suffered from carbuncles or boils or become 

 easily infected from slight causes. 



Conclusions.— 1. Leishman's method of 

 determining the phagocytic power of the 

 blood, as modified by Wright and Douglas 

 and by ourselves, is a very simple method 

 adapted to clinical application. 



2. Marino's stain is most appropriate for 

 demonstrating the leucocytes and the con- 

 tained bacteria. 



3. There is no uniformity in the phago- 

 cytic indices of the bloods of supposedly 

 healthy individuals. 



4. The phagocytic index of the same in- 

 dividual may be constant or it may vary 

 upon different days. 



5. An exceptionally low phagocytic count 

 usually indicates a present or past predis- 

 position to suppuration (the phagocytic 

 index in this regard being determined by 

 the use of Staphylococcus pyogenes au- 

 reus). 



6. The phagocytic index may not be be- 

 low the average in all cases in which there 

 has been a tendency to suppuration. 



The Value of the Voges-Proskauer Reac- 

 tion: Norman MacL. Harris, University 

 of Chicago. 



The red coloration at times met with in 

 fermentation tubes after testing the gas 

 composition with KOH solution, was first 

 described by Voges and Proskauer in 1898 

 as occurring in fermentation tube cultures 

 of certain members of the hemorrhagic 

 septicEemia group of bacteria, and the re- 

 action was advocated by them as a test for 

 differentiating members of this group. 

 However, as proposed by them, the test is 

 without value, because their observations 

 were made on bacilli which we now clearly 

 recognize as belonging to the hog cholera 



group, not to the hemorrhagic septicaemia 

 group. 



The color reaction has since been pro- 

 posed by Durham and MacConkey as a dif- 

 ferential test whereby B. lactis aerogenes, 

 B. mucosus capsulatus (Pfeiffer), and B. 

 cloacae and bacteria of such types may be 

 distinguished from certain intestinal and 

 other forms of bacteria. Howe and Mac- 

 Conkey likewise recommend it as possess- 

 ing value in the bacteriological analysis 

 of water. 



Contrary to the views of the foregoing 

 observers, the writer finds that the reac- 

 tion occurs irregularly with sueh bacteria 

 as B. coli, B. lactis aerogenes, B. mucosus 

 capsulatus (var. Pfeiffer, and Friedland- 

 er) , B. cholerce suis, B. enteritidis, B. icter- 

 oides, B. paratyphosus (several races), B. 

 proteus vulgaris, B. cloacce, B. fcecalis 

 aligenes and B. typhosus and Streptococcus 

 pyogenes. 



Conclusions.— 1. By Voges and Pros- 

 kauer the reaction was obtained not with 

 any member of the hemorrhagic septicaemia 

 group of bacteria, but with one of the hog- 

 cholera group. 



2. The writer finds that the reaction is 

 not confined to any one particular group 

 of bacteria, as found by Durham and Mac- 

 Conkey, but occurs widespread and irregu- 

 larly amongst bacterial species. 



3. As a differential test, the Voges-Pros- 

 kauer reaction is of little value. 



4. Its nature is at present unknown. 



The Protection of Cotton Stoppers during 



Sterilization: W. H. Manwaring and R. 



A. Akin, Indiana University. 



The falling of condensation-water in the 



autoclave is largely prevented by a disc of 



thinnest sheet copper, suspended about a 



quarter of an inch below the top of the 



autoclave, by means of a threaded bolt, 



placed in the opening to the pressure 



gauge. This bolt is flattened on two sides. 



