■o 



342 SUMMARY OF CURRENT RESEARCHES RELATING TO 



into permanent position, after which an ordinary key-hole saw was run 

 through the floor entirely around the contour of each girder, so that 

 each cleared the flooring and floor-covering by the thickness of a 

 saw-blade. The author describes fully the ingenious arrangements 

 whereby the girders, which clear the wall of the room by an inch or 

 two, carry the accessory apparatus. This apparatus is attached to them 

 in some instances by means of sliding one-sixteenth-inch sheet-metal 

 sleeves that may be clamped at any desired height ; in other instances 

 by other means. All parts are dead black. 



A second mode of installation involves bolting small vertical 

 I-shaped or Z-shaped girders to the masonry of the Ijuilding. 



A third mode depends upon the substitution of steel tubes, 3| ins. 

 to fi ins, internal diameter, for the girders. This method possesses 

 certain special advantages, inasmuch as the tubes are externally suitable 

 for the attachment of collars and sliding rings, and internally for the 

 reception of counterpoising weights. 



The author gives full descriptions and illustrations of all 

 arrangements. 



Fig. 22 shows the author's up-to-date microscopical laboratory, in 

 which the constructional work has been carried out on the first of the 

 above methods. 



B. Technique.* 

 tl) Collecting- Objects, including Culture Processes. 



Plating Dishes for the Cultivation of Bacteria.f — S. Delepine 

 makes the following communication : — Owing to the difficulty of 

 obtaining at the present time suitable dishes for making plate cultures I 

 have adopted several devices. 



1. The object of the first was to utiHze the stock of Petri dishes 

 which I had in the laboratory, which was insufficient when it became 

 necessary to have some eight hundred dishes available daily in 

 connexion with our military work alone. 



I had a number of shallow flat metal lids made to fit the tops and 

 bottoms of the existing dishes, so that each Petri dish could be utilized 

 to make two plates, thus doubling the stock available (fig. 23). I found 

 that these metal lids when well tinned answered their purpose. They, 

 however, require frequent polishing in order to keep the surface smooth 

 and free from rust. 



2. I have also made plating dishes by inserting round pieces of plate 

 glass in a thin rim of well-tinned metal or waterproofed cardboard, etc. 

 (fig. 24). These plating dishes are very much cheaper than the old- 

 fashioned Petri dishes, and appear to me to ))e better, because the glass 



* 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, etc. ; 

 (6) Miscellaneous. 



t Brit. Med. Journ., April 22, 1916. 



