532 SUMMARY OF CURRENT RESEARCHES RELATING TO 



ment which does not follow the direction of the movement of the 

 milled head. 



The following device has been designed to effectually prevent any 

 damage taking place. To the right-hand side of the limb, where the 

 micrometer drum-head is placed, a short piece of tube, threaded on the 

 outside, is fixed, and through it the fine-adjustment pinion passes, just 

 like the cannon pinion in a clock. An idle nut works on this screw in 

 a slot inside the micrometer drum. It is then arranged that this nut 

 will permit ten rotations of the fine-adjustment pinion to be made, and 

 then stop further motion by butting either against the side of the limb 

 or against the end of the inside of the' micrometer drum. Figs. 75 and 

 76 will make this simple device clear without further explanation. 



B. Technique.* 

 (1) Collecting: Objects, including- Culture Processes. 



Sugar Reactions for Diagnosis of Streptococci. f — Maas has 

 investigated the reactions obtained with fifteen different strains of 

 streptococci, cultivated in serum-pepton -water media, containing a 

 series of twenty-three carbohydrates, glucosides, and alcohols. The 

 author concludes that this method is not of any value for the classifica- 

 tion of streptococci. 



In discussing this communication, J. Koch stated that sugar media 

 were useful for the diagnosis of certain streptococci, and quotes as an 

 instance the mannite-acidifying property of Streptococmis Imigus, He 

 attributes the divergence of the results obtained by different investigators 

 to the impurity of commercial sugar preparations. 



Tellurium-media in the Diagnosis of Diphtheria. J— Schiirmann 

 and Hajos have investigated the value of the medium of Oonradi and 

 Troch for the isolation of diphtheria bacilli. This medium is made up 

 as follows : to a litre of water are added 10 grm. of meat extract, 5 grm. 

 sodium chloride, 20 grm. peptou, and 6 grm. of calcium bimaiate. 

 This is steamed for half an hour and filtered. Then is added glucose, 

 1 grm. per 100 c.cm. of filtrate. Then this fluid is added to fresh 

 ox-serum in the proportion of 1 to o, and 1 p.c. potassium tellurate is 

 added to the mixture, 2 c.cm. to every 100 c.cm. This is then heated 

 to 85'' C. for 15 minutes, when the medium solidifies. The action of the 

 calcium malate and potassium tellurate is to inhibit the growth of 

 intrusive organisms, while permitting that of the diphtheria bacillus. 

 Diphtheria colonies are black owing to their action on the medium, 

 liberating metallic tellurium. The authors, after comparative investi- 

 gations of a large number of cases, find that the use of this medium 



* This subdivision contains (1) Collecting Objects, including Culture Pro- 

 cesses ; (2) Preparing Objects ; (3) Cutting, including Embedding and Microtomes ; 

 (4) Staining and Injecting ; (5) Mounting, including slides, preservation fluids, etc. ;. 

 (6) Miscellaneous. 



t Centralbl. Bakt., Ite Abt. Ref., Ivii. (1913) Beih., pp. 258-62. 



X Centralbl. Bakt., Ite Abt. Ref., Ivii. (1913) Beih., pp. 56-61. 



