and Laboratory Methods. 



2201 



CURRENT BACTERIOLOGICAL LITERATURE. 



H. W. CONN, Wesleyan University. 



Separates of Papers and Boolcs on Bacteriology should be Sent for Review to H. W. Conn, 

 Wesleyan University, Middletown, Conn. 



Harris. Concerning an Improved Method of 

 Making Collodium Sacs. Cent. f. Bac. u. 

 Par. I, O, 32 : 74, 1902. 



The advantage of the use of collodium 

 sacs for bacteriological experiments 

 has come to be very thoroughly recog- 

 nized, but their use has been more or less prevented by the difficulty of making 

 them successfully. Harris describes a new method of preparing them which 

 simplifies all previous methods, and makes the preparation of a collodium sac 

 an extremely simple thing. For accurate description of the method one must 

 refer to the original article, but it is briefly as follows : 



Large gelatin capsules are obtained from a druggist (Fig. A), and while 

 closed, a glass tube is heated and thrust 

 through one end of the capsule for a 

 short distance (Fig. B), This is soon 

 fixed in position by cooling of the gela- 

 tine and serves as a convenient handle 

 for manipulation of the capsule. The 

 capsule is then coated by being placed 

 in a thick syrupy solution of collodium, 

 the collodium being allowed to coat 

 both the capsule and about one cm. of 

 the glass tube. It is then removed and ABC 



allowed to dry. There is thus pro- 

 duced a collodium sac on the outside of the gelatine capsule. The removal of 

 the gelatine from the interior is a simple matter. The capsule is filled with and 

 is immersed in hot water. The heat soon dissolves the gelatine, and then the 

 solution may be poured or drawn out of the capsule by a pipette, leaving the 

 collodium sac fastened to the end of the glass tube. The sac may then be filled 

 with any nutrient solution and the glass tube sealed in a flame if desired (Fig. 

 C). It is possible to remove the gelatine capsule in the process of sterilizing, if 

 desired, by simply filling the capsule with a nutrient bouillon after coating it 

 with collodium, immersing it in a dish containing bouillon and then sterilizing 

 it in an autoclav at 120°C. With such treatment the gelatine is both melted and 

 expelled from the collodium sac, leaving the sac filled with the sterilized nutrient 

 fluid. Such sacs may be conveniently used for demonstrating dialysis in class 



experiments. 



Linossier, G,, and Lemoine, Q. H. A Medico- 

 legal Investigation of the Source of Blood 

 by the Use of Precipitant Serums. Bui. de 

 r Acad. Med., March 25, 1902. 



difficult of solution. 



H. w. c. 

 A blood-stain being given, the deter- 

 mination of its source is one of the 

 problems most frequently met with in 

 legal-medicine, and one of the most 

 Until recently the only available method consisted in dilut- 



