390 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



(6) Miscellaneous. 



Illustrated Annual of Microscopy for 1900. 



[Contains some twenty-four interesting articles on various subjects.] 



Percy Lund, Humphries & Co., London. 



Fig. 99. 



B. Technique.* 

 CI) Collecting- Objects, including- Culture Processes. 



New Incubator.f — Dr. C. Tonzig describes a new incubator for 

 gelatin cultures whicb is said to be very satisfactory in its action. It 

 consists of a wooden case of which the horizontal measurements are 

 22 in. by 15 in., and the height 28 in. A tube of sheet zinc 3 in. 

 in diameter passes vertically through the middle of the wooden case, 

 and projects both above and below. At the lower end it is expanded 



into the shape of a flat-bottomed cone y 

 beneath which a gas-flame is placed. At 

 the upper end there is a thermometer, 

 and a thermo-regulator for the gas sup- 

 ply. The zinc tube is filled with water, 

 which is heated 10° C. above the tem- 

 perature required in the incubator. Ob- 

 servations made in the bacteriological 

 laboratories of the University of Padua 

 showed that the temperature thus pro- 

 duced in the incubator was constant and 

 uniform, and that when regulated to 20° 

 C.j it did not rise above 22°, so that 

 there was no melting of the gelatin, 

 even when the temperature of the room 

 rose to 19° C. (66° P.) 



Apparatus for Heating Cultures to 

 separate Spore-bearing Micro-organ- 

 isms.} — Dr. C. B. Stewart has devised an 

 apparatus which maintains a constant 

 temperature of 80° C. without any at- 

 tention. It is made of beaten copper, 

 and spun afterwards ; the inner chamber 

 is 18 cm. deep and 9 cm. in diameter. 

 The condensation tube (fig. 99) is 1 m. 

 in height. To use the apparatus a small 

 quantity of pure benzol, B.P. 80° C, is 

 poured into the jacket through the holo 

 for the condensation tube. A small 

 flame keeps the benzol boiling, and as 

 the vapour condenses in the condensa- 

 tion tube, and runs back, very little is lost. The chamber is filled to 

 about one-third of its depth with water at 80 9 C. When the lid is 



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

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

 (4) Staining and Injecting ; (5) Mounting, including slides, preservative fluids, &c ; 

 (6) Miscellaneous. ' t Lancet, 1900, i. p. 1014. 



X Centralbl. Bakt. u. Tar., l te Abfc., xxvii. (1900) pp. 366-7 (1 fig.)- 



