.246 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Heele's Miniature Spectroscopes.* — One form of these instruments, 

 •catalogued as No. 32, is shown in fig. 40. It has a symmetrical adjust- 



Fig.40. 



Fig. 41. 



able slit, comparison prism, achromatic lens and photographic micro- 

 meter scale for determining the position of the lines. The same 

 instrument, in a simpler form, with adjustable slit and achromatic lens, 

 is shown in fig. 41. 



B. Tech.nique.+ 

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



Simple Method for Clearing Nutrient Agar without Filtration.^ 

 H. Fischer recommends the following plan : A glass funnel of suitable 

 size is plugged with a cork just where the cone joins the tube, and 

 placed in an iron ring. Into this the boiling hot agar solution is 

 poured. It is then covered and placed in the cool. After some hours 

 the mass is found to be hardened, and all the turbidity is quite at the 

 bottom of the glass. The funnel is then inverted, and the agar with a 

 little help falls out. It is caught in the hand or a dish, and the turbid 

 part at the apex of the cone removed with a knife. The rest is then 

 remelted and poured into culture tubes. The method is not suitable 

 !for gelatin. 



Blood Cultures in Typhoid Fever.§— L. M. Warfield takes 10 to 

 15 c.cm. of blood in the usual manner from the arm, and distributes 

 it among four or five flasks containing 250 c.cm. of bouillon each, and 

 two or three containing the same quantity of litmus milk. The flasks 



* Catalogue (pp. 8-9), Peter Heele, London. 



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

 «esses; (2) Preparing Objects; (3) Cutting, including Imbedding and Microtomes : 

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

 (6) Miscellaneous. 



% Centralbl. Bakt., l te Abt., xxxv. (1904) p. 527. 



§ Bull. Ayer. Clin, l^ib. Pa. Hosp., 1903, No. l,pp. 77-80. 



