116 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



solution are added. In about twenty minutes 1 ccm. of formalin is added, 

 and in another twenty minutes the vessel is filled up with water. After 

 standing for 1-2 days the deposit, about 1 com., is removed and mixed 

 with 10 parts of liquid glycerin jelly. A drop of this is placed on a 

 slide and covered with a cover-slip. The preparation is then placed in 

 a closed glass jar containing a few drops of formalin. In the course of 

 a few days the external layer of gelatin becomes set by the action of 

 formalin, so that a ling of varnish or balsam becomes unnecessary. 



(6) Miscellaneous. 



Dropper for Sterile Fluids.* — G. Wesenberg describes a dropping 

 apparatus (fig. 32) which is of simple construction and of especial advan- 

 tage in disinfection experiments 

 for washing the disinfectant out 

 of the object to be tested. It 

 consists of a caoutchouc plug r 

 which is inserted into a test- 

 tube or the neck of a flask. The 

 plug has two perforations, one 

 for a bent tube a through which 

 air enters, and the other for the 

 bent tube b. The latter is nar- 

 rowed at c so that it can be 

 broken off or sealed up in the 

 flame. The way of using the ap- 

 paratus is obvious. If the fluid 

 does not flow freely it may be 

 forced on by blowing through a, 

 There is little chance of air- 

 infection if the end of 6 be held 

 close to a flame when the tube 

 is set upright after using it. 



Immersion Oil in Collap- 

 sible Tubes, f— C. W. Dodge 

 mentions that he has used im- 

 mersion oil stored in metal col- 

 lapsible tubes for over a year, 

 and has found the method satis- 

 factory and without signs of de- 

 terioration in the oil. 



Raising the Melting-point 

 of Gelatin by means of For- 

 malin.]: — Dr. J. G. C. Vriens 

 F IG . 32. alludes to H. J. van't Hoff's 



remarks on raising the melting- 

 point of gelatin by means of formalin, and points out that this property 

 was employed by Brown, in 1897, for hardening the gelatin layer of 



♦ Centralbl. Bakt., 1* AM, xxx. (1901) pp. 703-4:(l fig.). 



t Journ. Applied Microscopy, iv. (1901) p. 1567. 



% Centralbl. liakt., 1" Abt., xxx. (1901) pp. 74-2. [Cf. tins Journal. 1901, p. 719. 



