712 SUMMARY OF CURRENT RESEARCHES RELATING TO 



press on a cover-slip, the crystals forming as the mass cools. These 

 crystals may be watched forming under the Microscope any number of 

 times by simply warming the slide. 



The third principal method is confined to those substances which 

 are easily volatilised and crystallise on cooling. Some benzoic acid, 

 say, is placed in a dry narrow test-tube, and heated over the flame until 

 it volatilises. The tube is then inverted and made to stand on a slide. 

 The crystals form on the part of the slide covered by the tube, and, if 

 satisfactory, can be mounted in the usual way. 



Modelling and Reconstruction Method. * — Florence R. Sabin's 

 paper on the structure of the medulla, pons, and mid-brain of the new- 

 born is preceded by a clear description of the wax-modelling and re- 

 construction method, which will be found very useful by those inter- 

 ested in this procedure. 



Killing and Preserving Slugs, f — O. Goldfuss mentions the fol- 

 lowing procedures for killing slugs. The animals may be killed in the 

 extended condition by placing them in a glass vessel filled with water, 

 and capable of being hermetically closed by means of a glass plate. 

 Twenty-four to thirty hours usually suffice, but the action is more rapid 

 if a little carbolic acid be added to the water. Even better results are 

 obtained by adding a few drops of kreolin or of lysol, or 2-5 parts of 

 5 p.c. cocaine. As a preservative, alcohol, when used alone, hardens too 

 much ; but 60-70 p.c. alcohol, with a certain percentage of glycerin, is a 

 good preservative fluid. 3—5 p.c. formalin, to which about 5 p.c. of 

 alcohol or some glycerin is added, will be found extremely useful. 



(4) Staining- and Injecting:. 



Apparatus and Method for rapidly Staining large numbers of 

 Sputum Specimens. J — B. R. Rickards designed the apparatus shown 

 in fig. 162. It consists of a long narrow copper bath, mounted on legs 

 which are inclined and terminate in a broad base weighted with lead to 

 ensure stability. At one end near the top are two inlets ; the upper 

 one A for the admission of the stain, the lower one B for the water. In 

 the bottom of the bath is a small outlet C for the stain, closed by means 

 of a rubber tube and a pinch-cock. At the other end of the bath, par- 

 titioned off by a false wall, is a i in. siphon, the inner end of which 

 is left at least £ in. from the bottom, to prevent the effect of capillarity. 

 The bottom of the bath is 8 in. above the base. The entire appara- 

 tus is nickel-plated. Instead of the ordinary slide, a piece of thin 

 plate glass 9 by 3 in. is used. It is etched as shown in the dia- 

 gram, fig. 163 ; the rough surface above the spacings is for writing the 

 names of patients with a blue pencil. Several of these plates can be 

 manipulated simultaneously. Carbol-fuchsin and Loeffler's methylen- 

 blue are used for staining, and 3 p.c. HC1 in 95 p.c. alcohol as the 

 decoloriser. The technique is as follows. Carbol-fuchsin is admitted 

 through A until the bath is about two-thirds full. The bath is then 

 heated by means of a "Bunsen's burner, and while the heating is in 



» Johns Hopkins Hosp. Rep., ix. (1900) pp. 925-1045 (8 pis. and 45 figs.). 



t Zeitschr. angew. Mikr., vii. (1901) pp 85-90. 



t Joura. Boston Soc. Med. Sci., v. (1901) pp. 391-4 (2 figs.). 



