ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 253 



results from the three methods : thus by Much's method, which is only a 

 reinforced Gram, the staining persisted for the longest time. One 

 species (Grass bacillus) which lost its capability to stain by Ziehl's 

 method after an irradiation of 5 minutes, was still stainable by Gram's 

 method after 60 minutes' exposure. Bovine tubercle lost the power to 

 stain by Gram's method in 20 minutes, but could be stained by the 

 Ziehl procedure after 30 minutes' exposure. Exposure in the moist 

 state, i.e. as emulsion, still further diminished the power to stain by 

 Gram's method, while the capacity to stain by the Ziehl method was 

 retained much longer. 



Staining Capsulated Bacteria in Body Fluids.* — W. H. Smith 

 gives the following procedure for staining capsulated bacteria : — 1. A thin 

 smear from sputum, lung, pleural or pericardial exudate is fixed in the 

 flame and then covered with 10 p.c. aqueous solution of phosphomolybdic 

 acid for 4 or 5 seconds. It is then washed in water. 2. If the bacterium 

 be Gram-positive, the smear is treated by Gram's method and counter- 

 stained with 6 p.c. aqueous solution of eosiu for ^ to 1 minute, warming 

 gently. The capsule is eosiu-stained. 3. If the organism be Gram- 

 negative after the phosphomolybdic acid and washing, proceed as 

 follows : Stain with 6 p.c. aqueous solution of eosin, warming gently 

 for J to 1 minute. Wash in water and counter-stain with Loeffler's 

 methylen-blue solution for ^ to ^ minute, then absolute alcohol and 

 mount in balsam. The capsule is eosin-stained and the body of 

 the bacterium blue. The illustrations to this paper show the capsules 

 very distinctly. 



Metallography, etc. 



Magnesium-silver System. t — W. J. Smirnow and N. S. Kurnakow 

 point out the difficulty of distinguishing, by thermal methods, between 

 a soUd solution and a definite compound in the case in which the com- 

 pound forms solid solutions with the components on either side of it in 

 the equilibrium diagram. Such a case occurs in the magnesium-silver 

 system, and the authors show that the compound MgAg corresponds 

 with a maximum in the curves of electrical conductivity and of tempera- 

 ture co-efficient of resistance. The existence of MggAg is also indicated. 

 All the phases occurring in this system are of variable concentration. 

 The results were confirmed by hardness measurements and microscopical 

 examination. The general character of conductivity and hardness 

 diagrams of systems containing compounds is discussed ; the compound 

 may or may not decompose on melting ; both cases are considered. 



Phosphor Bronzes. |—M. Levi-Malvano and F. S. Orofino have in- 

 vestigated, thermally and microscopically, the ternary system Cu-OugSn- 

 CugP, which includes the commercial phosphor bronzes. The two 

 compounds CugP and CugSn are immiscible in the solid state ; the 

 diagram of this binary system shows a eutectic point at 22 p.c. CugP and 

 650° C. In the ternary system the phases present in the solid alloys are 



* Publications Massachusetts Gen. Hosp., iii. (1911) pp. 488-92 (6 figs.). 

 t Zeitschr. Anorg. Ohem., Ixxii. (1911) pp. 31-54 (7 figs.). 

 i Gaz. China. Ital., xli. (1911) 2, pp. 297-314, through Journ. Soc. Chem. Ind., 

 XXX. (1911) p. 1390. 



