190 Hub er: Method of preparing large Nurabers of Sections. XXIII, 2. 



features. This I believe has been accoraplished by combining the warm- 

 water method of flattening paraffin sections with the Obregia-Gulland 

 method. This procedure is simple and gives satisfactory results. It is 

 here described in detail with the hope that it may prove useful in other 

 laboratories. 



Embedding and Seetion Cutting. It is possible to ciit serially 

 on an aiitomatic microtome uearly all tissues and Organs after em- 

 bedding in paraffin, — decaleified bone and tooth, tendon, fascia, 

 penis and central nervons System when desired for the Weigert 

 myelin stain (?) may be mentioned as exceptions, Necessary is, 

 however, a thorongh dehydration of the tissue-blocks to be embedded 

 and cut, which is readily obtained by renewing several times the 

 absolute alcohol used for dehydration and further a complete dis- 

 placement of the alcohol by xylol followed by a thorough penneation 

 of the tissue-blocks with paraffin. In accomplishing the latter step 

 we have found very useful the method suggested by Kolster (8), 

 namely permeating the tissues with paraffiii in partial vacuum. The 

 method of procedure used here in this laboratory for embedding of 

 tissues in paraffin is as foUows : The tissue-blocks , after thorough 

 dehydration and permeation with xylol, are placed for a few hours 

 in a mixture of equal parts of xylol and soft paraffin (melting point 

 45^), are then transferred for several hours into soft paraffin and 

 for another few hours in liard paraffin (raelting point about 52*^). 

 Before embedding in the paraffin , the bottle used as Container is 

 fitted with a rubber cork through which has been passed a short 

 glass-tube the free end of which is connected by means of a thick 

 walied rubber tube to a Chapman's suction pump, by means of which 

 a })artial vacuum is readily obtained and maintained in the bottle 

 containing the tissues to be embedded. Several devises may be 

 used for keeping the paraffin melted during this step. The glass- 

 bottle containing the tissues may be placed on a warming plate, 

 heated from one end with a flame to a sufficient extent to keep 

 the paraffin in the bottle melted. A little experience soon enables 

 one to judge of the size of flame necessary to heat the paraffin to 

 a little above its melting point. The bottle containing the tissues 

 and paraffin may be placed in a water-bath partially filled with 

 water and the water heated to two or three degrees above the 

 melting point of the paraffin used , or the bottle may be placed in 

 the paraffin-oven and the rubber tube connecting it with the Chapman's 

 suction pump allowed to pass through the cover of the compartment 



