and Laboratory Methods. 1335 



stains: thionin, methyl blue, methylen green, safranin, toluylen red (neutral red), 

 nigrosin soluble in alcohol, indulin ; (3) Azo stains : chrysoidin, vesuvin, bis- 

 marck brown, the last two being probably the same ; and (4) Acridin stains : 

 chrysanilin. All these stains penetrate the living cell most rapidly, only rhodamin 

 is somewhat slower. Quite different is the effect of the sulphuric acid stains. 

 (1) Acid fuchsin, acid green, acid violet, anilin blue soluble in water ; (2) Ni- 

 grosin soluble in water, and indulin ; (3) Congo red, ponceau red, bordeaux 

 red, biebricher scarlet; and (4) Indigo carmin, all penetrate neither animal nor 

 plant cells. Only the acid stains belonging to group three {Azo stains), methyl 

 orange and tropaolin 00 and 000 are an exception, since these act in some cases 

 after long immersion. Eosin and acid carmin are in general not taken up, 

 curcuma acts quickly, carthamin more slowly. Since all the studies agreed that 

 all the substances easily soluble in fatty oils and similar substances were taken 

 up quickly by living cells, while those insoluble or soluble with difficulty did 

 not penetrate living cells, the conclusion was obvious that the osmotic con- 

 dition of living cells rests on the phenomena of selective solution. Especially 

 was the author drawn to this conclusion since the plasma-skin of cells is im- 

 pregnated with cholesterin or a mixture of cholesterin and lecithin. It especi- 

 ally concerns these anilin colors, since all the commercial salts are basic anilin 

 stains mixed with cholesterin, or else are easily soluble in a strong solution of 

 cholesterin or lecithin in organic fluids. Also these liquids in a pure condition 

 have no solubility for these dyes. Tannic acid-methylen blue, which does not 

 penetrate the living cell, is also wholly insoluble in cholesterin and lecithin solu- 

 tions. With a few exceptions all the sulphuric acid stains and acid carmines are 

 completely insoluble in these liquids. Methyl orange and tropaolin are excep- 

 tions and penetrate very slowly and slightly into the living cell. a. m. c. 



_ ^, ^ ^ , . , , „ , For this work sublimate solution, Zen- 



Retterer, t. Transformation de la cellule car- 



tilagineuse en tissue conjunctiv reticule. ker's and Flemming's fluids and also 

 Comp. Rend. See. de Biol. 51 : 904-907, an aqueous solution of platinic chloride, 



1 pt. to 1000, were used. Without 

 previous decalcification, objects such as the ribs of rabbits and guinea pigs, 

 are embedded in paraffin. The following combination of stains gave the best 

 results : after leaving the sections for a few hours in a solution of safranin in 

 anilin water, they are washed out in water, stained for a few minutes in Boehmer's 

 haematoxylin, and decolorized in alcohol to which a very little picric acid is 

 added. a. m. c. 



Petroff, N. Neue Farbungmethod ziir rothe Up to now the contrast-staining of 

 Blutkorperchen in Schnittpreparaten. Bol- blood corpuscles has been done by the 



nicznaia Gazeta Botkina, iSgg. (Russian.) r ^ • r .1 1 u-^ 



■* > vv V ' ygg Qf stams from the malachite-green 



group, which differentiate by virtue of the special characters of red blood cells. 



This process is as follows : material previously fixed in Miiller's fluid or formalin, 



or Orth's mixture, is embedded in paraffin, not collodion, cut into the thinnest 



sections possible of regular thickness, and fastened to the slide. The paraffin is 



then taken out with xylol and the sections washed in alcohol and water. (2) 



Nuclear staining is done by putting the sections for 10-15 minutes in a concen- 



