46 



THE AMERICAN MONTHLY 



[March, 



4th. Shake in absolute alcohol for 

 a few seconds. 



5th. Put in oil of cloves for ten 

 minutes. 



6th. In clean oil of cloves for ten 

 minutes. 



yth. In half a drachm of benzole 

 for five minutes. 



8th. Mount in Canada balsam 

 softened with benzole. 



The benzole may be omitted, as it 

 sometimes slightly contracts delicate 

 tissue, but it causes the mounting to 

 harden much more rapidly, and, 

 perhaps, is beneficial in preserving 

 the magenta. 

 Process II. — To Stain Sections in 



JSIagenta and Blue Compound. 



I St. Mix seven drops of a one- 

 grain solution of magenta with five 

 drops of a two-grain solution of blue 

 (non-acid) . 



2d. Into this purple mixture put 

 your section for five or ten seconds. 



3d. Shake rapidly in absolute al- 

 cohol for a few seconds. 



4th. Treat with oil of cloves and 

 benzole, as in Process I. 

 Process III. — To Stain Sections in 

 Green Anilin and Carmine. 



1st. Put vour section in a three- 

 grain solution of iodine-green, and 

 let it remain for one or two hours. 



3d. Soak in alcohol for five or ten 

 minutes, for reasons given above. 



3d. Put in water for a minute. 



4th. In the borax carmine from 

 thirty to forty-five seconds. 



5th. Shake rapidly in water, and 

 soak out any excess of carmine that 

 inay be taken up. 



6th. Put in alcohol for five minutes. 



7th. In clean alcohol for ten min- 

 utes. 



Sth. In absolute alcohol for ten 

 minutes. 



9th. In oil of cloves for fifteen 

 minutes. 



loth. Mount. 

 Process IV. — To Stain Sections in 

 Green Anilin and Carmine 

 Cofnpotmd. 



I St. Mix fifteen drops of borax 



carmine with fifteen drops of the 

 three-grain iodine-green solution. 



3d. Transfer section from alcohol 

 to water for a minute. 



3d. Put in the dye from thirty to 

 sixty seconds. 



4th. Shake rapidly in water, and 

 soak out any excess of carmine that 

 may have been taken up. 



5th. Treat with alcohol and oil of 

 cloves as in Process III. 



Ammonia carmine may be used in 

 the same proportion as the borax. 

 Formerly, in Process III, I used the 

 carmine before the green, but I now 

 follow Dr. B. W. Barton's plan of 

 using the green first, as far better re- 

 sults are therebv obtained. 



To stain sections in hasmatoxylin 

 and anilin blue, the mode of proced- 

 ure is the same as for leaves ; but 

 they stain more rapidly, and only re- 

 quire the dilute dye. 



Whether sections are stained by the 

 alternate, or by the compound meth- 

 ods, the selection of colors is the 

 same. The red and green anilin and 

 the haematoxylin go to spirals, bass 

 cells, scattered thickened cells, and, 

 sometimes, to thick epidermis and 

 hairs. 



The blue anilin and carmine always 

 go to parenchymal and often to thin 

 epidermic and hypodermic tissues. 

 The selection of color in matured 

 wood is diftbrent, as will be seen 

 further on. 



It is not possible, I think, to give 

 a satisfactory explanation of double 

 staining of either animal or vegeta- 

 ble tissues. We can only say that 

 certain dyes seem to have an affinity 

 for certain cells. This is best shown 

 by soaking single stainings in a fluid 

 that removes their color. If sections 

 stained in red or in green anilin be 

 soaked in alcohol, and those stained 

 in haematoxylin in alum-water, the 

 color will rapidly leave the loose 

 parenchyma, but will be retained for 

 many davs bv the denser cells, as 

 spirals, bass, etc. 



On the other hand, specimens 

 stained in blue anilin, if left in alco- 



