Journal of Applied Microscopy. 481 



fifty-five days, the urine was sterile throughout. In a few cases the cocci were 

 present for a few days, and then disappeared. As a rule the number of 

 micro-organisms eliminated increased with the course of the process. Micro- 

 scopic examination of the kidney in early cases shows in the cortex desquamation 

 of the tubular epithelium. In later cases there is slight fatty degeneration of the 

 epithelium of the loops. Small cell infiltration and frank nephritis does not 

 occur. Cocci are often seen in the glomerular tufts, less often in the inter- 

 tubular capillaries, rarely within the tubules, and never in the capsular space. 



,., „ ^ . , ^ . Bouillon cultures of streptococcus of varying 



Wallgren. Peritoneal Cavity. ^ . . , 



virulence were injected, and fluid withdrawn 



after different intervals of time. Generally a fatal peritonitis resulted. The 

 peritoneum can get rid of very small doses of virulent organisms with 

 only a slight infection at the point of inoculation. Streptococci of slight viru- 

 lence do not develop in the peritoneum if only a small amount of fluid is 

 injected with them. The peritoneum is protected by its great power of absorp- 

 tion, the activity of the leucocytes normally in it and those which emigrate to it, 

 and possibly by the activity of the endothelial cells. The leucocytes act by 

 phagocytosis, by the products of their degeneration, and possibly also by their 

 secretions. With very virulent streptococci there is marked phagocytosis at the 

 beginning of the infection, later it is lacking; with organisms of slight viru- 

 lence, the phagocytosis persists uninterruptedly as long as streptococci are 

 present in the peritoneal cavity. As long as streptococci are present, and for 

 two or three days after their disappearance, the majority of the cells are poly- 

 morphonuclear leucocytes. After this time the mononuclear leucocytes 

 predominate. R. m. p. 



NOTES ON RECENT MINERALOGICAL 

 LITERATURE. 



Alfred J. Moses and Lea McI. Luquer. 



Books and reprints for review should be sent to Alfred J. Moses, Columbia University, 



New York, N. Y. 



Graetz, L. Die Rontgenstrahlen in Beziehung The writer gives under five groups a 

 auf Mineralogie und Krystalloaraphie. Zeit. ^ • r ^ ^ ^ r ^, 11 i 



f Krvst 30: 610-618 iSqq brief statement of the work done and 



lists of the publications. 



I. Absorption of the Roentgen Rays. — The permeability is dependent upon the 

 density. In general, the denser substance absorbs most ; that is, with elements 

 and salts the absorption is greater as the molecular weight increases. Calcite 

 absorbs more than its density warrants. Carbon and its combinations with 

 oxygen, hydrogen, and nitrogen are relatively very transparent, while sulphur, 

 phosphorus, and especially iodine, make substances relatively opaque. Phos- 

 phates absorb less than arsenates. 



X-rays produced in very high vacuum are less absorbed than those from 

 lower vacuum. . 



