ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 21o 



with the same precautions as in a surgical operation. Each step is 

 important and therefore the description cannot be satisfactorily con- 

 densed. 



Thermos Apparatus in Laboratory Work.* — J. L. Kritschewsky 

 discusses the use of the "thermos" flask for scientific purposes, and 

 points out that for cultural work, as well as for general pathological 

 work in small laboratories, such apparatus may act as a fairly efficient 

 substitute for a thermostat. Culture tubes inoculated and enclosed in 

 a metal case are put into the flask and water at 38° C. is poured in. In 

 this manner cultures of Gonococcus, Staphylococcus aureus, and other 

 organisms may readily be obtained. The author describes a form of 

 test-tube rack to fit the flask, with the help of which he has been able 

 to carry out serological investigations, such as Wassermann and agglu- 

 tination reactions. A larger type of flask than those at present 

 available would be of use. 



New Anaerobic Methods.! — M. Ogata and M. Takenouchi describe 

 two simple methods of plate culture under anaerobic conditions. The 

 apparatus required is as follows. Petri dishes, of two different sizes 

 (10 cm. and 13 cm. diameter), a piece of glass rod bent into triangle 

 form, a glass U-tube, potash, pyrogallic acid solution, and fluid paraffin. 

 The necessary plate culture is made in the smaller-sized Petri dish on 

 glucose-gelatin or agar. The large dish is half filled with 5 p.c. pyro- 

 gallic acid solution, the glass triangle is placed in position in this solu- 

 tion, a small piece of solid potash is put into the pyrogallic acid, and 

 the inoculated culture plate inverted and set resting on the glass triangle. 

 A piece of absorbent paper placed in the pyrogallic solution prevents 

 frothing. The surface of the solution beyond the margins of the 

 inverted culture-plate is covered with liquid paraffin. The cover of the 

 large Petri dish is then placed over all. 



In the second method, instead of a glass triangle, is used a circular 

 glass trough of a sufficient diameter and size to permit of the margin of 

 the inverted culture-plate resting within the trough. Three glass feet 

 raise this trough from the bottom of the large Petri dish, which con- 

 tains, as in the first method, pyrogallic acid and potash. The trough 

 itself contains mercury, thus forming a perfectly air-tight joint all round 

 the margin of the culture-plate. The free surfaces of pyrogallic are 

 covered as before with liquid paraffin. In order to avoid splashing when 

 removing the plate, air is introduced by means of a bent tube as shown 

 in the diagram. 



"*>■* 



Diagnosis of Diphtheria. — E. Gildemeister and Giintherf have 

 investigated certain recent methods for the demonstration or isolation 

 of diphtheria bacilli. They first discuss the staining method of Gins, 

 which consists of the following steps: stain with Neisser I (acetic 

 methylen-blue) for a few seconds ; wash ; treat with Lugol's iodin 

 containing one p.c. lactic acid for five seconds ; wash well and counter- 



* Centralbl. Bakt., lte Abt. Orig., lxxiii. (1914) pp. 77-80. 

 t Centralbl. Bakt., lte Abt. Orig., lxxiii. (1914) pp. 75-7. 

 % Centralbl. Bakt., lte Abt. Orig., lxxii. (1913) pp. 237-45. 



