45^ Proceedings Columbia Biochemical Association [April 



micro-amino-nitrogen apparatus of Van Slyke, it makes an admir- 

 able outfit for work with small amounts of protein. 



During digestion, the tiibe with the bulbs is inserted into the 

 absorber, B, and the fumes from the 200 mm. Jena test-tube, /, 

 are carried to the sink through the pump, PM, via tube S, which 

 may have a half dozen openings, so that a number of determinations 

 may be conducted at the same time. Since much water vapor is 

 lost during digestion, Pregl passes steam from a flask, /, to the 

 bottom of the Jena test-tube, J, through the long small-bore tube, 



A, which is fused into the bulb through which it passes. It is quite 

 necessary to pass steam in this way. Neutralization is effected with 

 sodium hydroxid Solution poured down tube A, after the apparatus 

 has cooled; if the hydroxid is added immediately after digestion, 

 tube A will frequently crack. After neutralization, the upper end 

 of tube A is closed by a clamp or glass rod introduced into the 

 rubber connection and distillation is effected by connecting tube R, 

 which dips into the decinormal acid in the beaker P. This should 

 be done, as a matter of fact, before neutralization, so that no am- 

 monia is lost. In place of distilling by heat, Folin's method for 

 Urea may be introduced, by driving an air current through A, and 

 the only precaution necessary is that the current be sufficiently 

 strong to drive all of the gas into the distillation tube, R. The 

 bulb at the lower end of the distillation tube, R, prevents back- 

 suction, as sometimes occurs. 



The Jena test-tube fits loosely the collar of the apparatus above 

 it, and the water-vapor condenses sufficiently around it to insure an 

 air-tight Joint. There is Variation in Jena test-tubes of 200 mm. 

 length, but it is small, so that the apparatus fits practically any such 

 tube. The apparatus is made by the Emil Greiner Company, New 

 York City. 



B. ABSTRACTS OF PAPERS FROM THE COLUMBIA BIOCHEMICAL 



DEPARTMENT AND AFFILIATED LABORATORIES 



70. The calcium content of tuberculous areas in lung tissue. 



Max Kahn. Wherever the tubercle bacillus lodges it induces a 

 deposition of calcium salts, which hinders the ingress of other 

 bacilli. The body in general becomes poorer in lime salts. It was 



