200 



Scientific Proceedings (114). 



99 (1681) 



A clinical method for the quantitative estimation of calcium in 



blood. 



By MAX KAHN and L. G. HADJOPOULOS. 



[From the Department of Laboratories, Beth Israel Hospital, New 



York City.] 



To 1 c.c. of blood serum in a 10 c.c. test-tube, add 4 c.c. of a 

 1 per cent, solution of ammonium oxalate. Let stand for to 

 I hour, and centrifuge for 5 minutes. Pour off the supernatant 

 fluid. Wash the precipitate three times with distilled water, 

 recovering the precipitate by means of centrifugalization. Add 

 to sediment 1 c.c. distilled water and transfer to a vitreosil crucible. 

 The test-tube is washed with distilled water and the washings 

 also collected in the crucible. The water is slowly evaporated, 

 and the precipitate burnt in a strong flame until CaO is formed. 

 Dissolve the ash in }4 c.c. N/50 HC1, add 1 c.c. distilled water 

 and titrate excess of HC1 with N/100 NaOH, using phenolphtha- 

 lein as an indicator. The amount of CaO can now be calculated. 



Eight analyses may be made by this method in one hour. 

 Remarkably uniform results are obtained upon repeated examina- 

 tions of the same blood. For clinical purposes, this method is of 

 great assistance. 



100 (1682) 



The penetration of normal mucous membranes of the rabbit by 

 Treponema pallidum. 



By WADE H. BROWN and LOUISE PEARCE. 



[From the Rockefeller Institute, New York City.] 



The fact may be recorded that highly virulent strains of 

 Treponema pallidum are capable of penetrating some portion of 

 the genital mucosa of normal rabbits and setting up an infection 

 without necessarily producing the first gross lesion at the portal 

 of entry. This fact was recently determined in 9 rabbits and with 

 two highly virulent strains of Treponema pallidum. 



