492 SUMMARY OF CURRENT RESEARCHES RELATING TO 



errors in spacing. The writer has described this method in this Journal, 

 July 1874. 



These errors had apparently no periodicity snch as would be expected 

 to result from the screw motion on a ruling machine of the ordinary type. 

 It also became apparent that the lines were curved, and it was estimated 

 that the radius bar or spring-pole holding the mling point was approxi- 

 mately eight feet in length. 



We can see that this gives an insight into Nobert's methods ; and 

 the inference is that his most delicate ruled bands did not require the 

 use of a screw or a sliding mechanism. The curvature of lines shown 

 in his rulings W"uld result from the ruling point being carried by a 

 spring. The diminishing depth of ruling as the closest lines are 

 approached may have been accomplished by placing the ruled surface in 

 an oblique position rather than by a diminished magnetic pull on the 

 spring carrying the diamond. 



The indications are that in ruling his finest bands of lines, Nobert 

 depended entirely upon changes of temperature through measured time 

 intervals to give the required spacing. 



B. Technique.* 

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



Simple Method of Preparing Tissue-cultures.t — E. C. Rosenow 

 recommends the following procedure for the bacteriological examination 

 of pathological tissues. While in most infections, the investigation of 

 normal body fluids and pathological exudates by the familiar laboratory 

 methods give satisfactory results, in the case of extirpated lymphatic 

 glands in Hodgkin's disease, the tissues in rheumatoid arthritis or 

 arthritis deformans, gastric ulcers, and so forth, the ordinary methods of 

 technique are not reliable, and the emulsification of the tissues under 

 absolutely sterile conditions becomes necessary. 



The apparatus consists of a metal drum, 28 by 1*.) cm., with a 

 circular opening at one end, through which a long-sleeved thick-woven 

 glove, lined with cotton-wool, is introduced and attached to the margin 

 of the opening. On the upper surface of the drum a mica window is 

 let in, for observation purposes, and at one side a round opening 

 2*5 cm., corked with cotton wool, is made. This opening is used for 

 the purpose of introducing and abstracting material. The drum also 

 contains a fixed shallow bowl, pestle, forceps, scissors, and test-tube. 

 The whole apparatus is sterilized for an hour at 160° C. before use. 



The aseptically removed pieces of tissue for examination are super- 

 ficially sterilized by passing through the Bunsen flame, or by plunging 

 into boiling water, and are then placed in sterile salt solution. The 



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

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

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

 (6) Miscellaneous. 



t Centralbl. Bakt. lte Abt., lxxiv. (1914) pp. 366-8. 



