11G SUMMARY OF CURRENT RESEARCHES RELATING TO 



The material, which may be "fruiting" or sterile, is gathered in 

 jars and brought home in water, or can be placed directly in the fixing 

 solution at the time of gathering, this last l>eing generally preferable. 

 If fixed in the chromo-acetic mixture it will require about 12 hours 

 for thorough fixation, and 24 hours in the formalin. After chromic- 

 acid, the material must be washed in running water or frequent changes 

 for at least one hour, or, better, for three hours. The following simple 

 little piece of apparatus is very useful for washing. It consists of a 

 test-tube fitted with a cork, through which two pieces of glass tube pass. 

 One of these is connected to a water-tap by a piece of rubber tubing, 

 which, in turn, is connected to a piece of glass tubing passing through 

 a cork jammed in the mouth of the tap. A piece of thin muslin is 

 tied over the end of the other tube inside the jar to prevent the escape 

 of specimens. With formalin no washing is necessary. 



The material being fixed, the next question is the stain. If nuclei 

 are the only details required, hamialum will be the best to use. It 

 should either be used strong for 5 minutes, or diluted (1 c.cm. to 

 50 c.cm. of water) for 24 hours. The staining must be carefully 

 watched in both cases. Overstating may be remedied by water acidu- 

 lated (0*1 p.c.) with hydrochloric acid, but the method is somewhat 

 risky. The other methods of staining are as follow : stain with iron 

 alum solution for 3 hours, wash in running water for 1 hour. Stain 

 in hematoxylin solution for G-12 hours. Now comes the delicate part, 

 for the tissues are much overstained, and must be washed in the iron 

 ;solution till the details are brought out, examining with the Microscope 

 the whole time. Immediately the details are out (generally in about 

 a quarter of an hour) the decolorisation is stopped by placing the object 

 in tap or rain water. Now place some water in a watch-glass and add 

 5 p.c. of glycerin. Transfer the algae to the dilute glycerin and cover 

 it with an inverted watch-glass, to prevent dust without checking 

 •evaporation. Leave until the glycerin is thick enough for mounting, 

 mount in a shallow tin cell in just enough glycerin to fill the cell (this 

 requires some practice), seal with gold size, and when dry ring with 

 Brunswick black. In some cases a contrast stain may be desired. This 

 can be obtained by placing the tissue in the eosin solution for 30 seconds 

 or less, previous to the transference to the 5 p.c. glycerin. 



(5) ^Mounting-, including' Slides, Preservative Fluids, &c. 



Two Methods for Comparing Normal with Abnormal Tissues 

 under the Microscope.* — S. G. Shattock and C. F. Selous exhibited 

 sections illustrating the above, which they named the method of super- 

 position and that of the composite block. The methods were more 

 particularly adapted for class purposes, and were more especially 

 applicable in the study of bone marrow, the central nervous system, 

 and the blood. Ti.e plan of superposition consisted in mounting a 

 normal section directly underneath the diseased, that is, without the 

 intervention of a second cover-glass, so that by merely altering the focus 

 the two could be studied in rapid succession. The sections should be 



* Rep. Path. Soc. Nov. 1, 1904. See Brit. Med. Journ., 1904, ii. ]>. 1249. 



