THE MICROSCOPE. 



^^cljCi:tl0iJts, 



On a Convenient Method of Imbedding. — The following 

 method of imbedding was worked out by Dr. Justus Gaule, of the 

 Physiological Institute, Leipzig, Saxony, by whom it was communi- 

 cated to the writer. I have tried it on all sorts of tissue and can 

 fully recommend it. 



A piece of tissue of convenient size is to be taken, treated with 

 the ordinary re-agents and stained in the mass. If large, it may be 

 convenient to remove it from the staining fluid to alcohol for a few 

 hours and then replace it. When thoroughly stained, the specimen 

 is to be put in seventy per cent, alcohol for about twelve hours, 

 then transfer to absolute alcohol until it is completely dehydrated. 

 Then put it in oil of cloves over night, or leave it there until it is 

 convenient to imbed it. 



Place it in turpentine half an hour, — large specimens for a 

 longer time — then transfer it to a mi.x.ture of turpentine and paraf- 

 fine, kept melted on a water-bath at about 40" C. In this the speci- 

 men, if from liver or intestine, etc., should remain for an hour or 

 more; small nerves and blood-vessels of course need not remain so 

 long. Then transfer it to a l)ath of pure paraffine, melted at a tem- 

 perature of 60" C, and leave it for the same length of time. Indeed, 

 if care be taken that the temperature does not materially exceed 60", 

 the specimen may remain as long as convenient. When the tissue is 

 thoroughly saturated with melted paraffine, a small i)aper box 

 may be filled with melted paraffine and the specimen placed in it to 

 cool. If properly imbedded, a cut surface has a smooth and shining 

 appearance. No line of division must appear between the specimen 

 and surrounding paraffine. The whole mass should cut, as nearly 

 as possible, like one homogeneous mass of paraffine. 



The subsequent handling of the sections varies with their na- 

 ture. Moderately thick sections of firm tissue may be placed in tur- 

 pentine to remove the paraffine and mounted as usual in chloro- 

 form-balsam. Thin specimens, or those which come to pieces when 

 the paraffine is removed, like thin sections of liver, etc., may be laid 

 on the slide on which they are to be mounted and the paraffine 

 washed out by benzine, carefully applied with a dropping-tube; 

 allow the benzine to evaporate, then lay on the cover-glass and ap- 



