118 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



0*9290 and 1*224:2, while that of tubercle bacilli varied between 

 1*0110 and 1*0760. The sputum is, therefore, sometimes lighter and 

 sometimes heavier than the bacilli. The author accordingly proposes 

 to ensure its always being heavier by the addition of an equal volume 

 of a 25 p.c. salt solution, a drop of ammonia having previously been 

 added. By this means the bacilli are always found in the surface layers, 

 after centrifugalising, a drop being removed thence by means of a 

 capillary pipette, placed on a slide, dried, and stained in the usual way. 

 The added salt does not cause any difficulty in staining. The author 

 has also devised an instrument which he names a " Sputumdensimeter,"' 

 for the ready determining of the specific gravity of sputum. 



(4) Staining and Injecting - . 



Modification of Teichmann's Injection Syringe.*— Sieber describes 

 some improvements which he has effected in this syringe (fig. 20). The 



Fig. 18, 



end of the piston-rod is grooved, so that, though fixed to the plunger, 

 ] otary movement is permitted. The end-cap of the syringe snaps on 

 by means of a bayonet-joint, and this is quite independent of the piston- 

 l od screw. Handles attached to the syringe afford a firm grip of the 

 instrument. A two-way cock (fig. 19) attached to the nozzle allows 

 the syringe to he refilled without disturbing the apparatus or unfasten- 



* Aimf. Anzo'g, nv. (1903) pp. 7-10 (7 figs.). 



