1416 Journal of Applied Microscopy 



followed by their final passage into the blood and chyle. The fat, appears to 

 pass into the adenoid meshes in comparatively large particles and here 

 disappears as if in solution. It is frequently taken up by leucocytes, in the 

 central chyle vessels which have been filled by absorption abundant fat occurs 

 in the form of a very fine emulsion. The albuminous substances cannot be 

 demonstrated by fixatives and stains, but the protoplasmic network surrounding 

 these substances can be demonstrated. Till they reach the central chyle vessel 

 each drop is undoubted albumin. a. u. c. 



Benda, C. Eine Makro-und Mikrochemishe The author applied Weigert's method 



Reaction der Fettegewebsnecrose. Vir- for neuroglia demonstration tO Other 



chow's Arch. Bd. i6i, iqoo. i • ^ i • i l- ^ rr^i 



^ histological subjects. The tissues are 



hardened in a 10 per cent, formalin solution, then after one or several days put 

 into Weigert's Neuroglia mordant, a mixture of copper acetate, chrom-alum 

 and acetic acid. This impregnation is best accomplished in an incubator, 

 with the exception of the bony substance, which is a deep blue from the copper 

 salt, all the other organs after a week's treatment in this mordant take a pale 

 green grey color, somewhat bleached by washing with water. The necrotic fat 

 tissue ( omentum with a little of the pancreas ) appears after 24 hours' treatment 

 in the incubator covered with green flakes or rust, both on the surface and deep 

 in the tissue. 



It was easily ascertained that it was the copper solution that caused this 

 color and that it was the necrotic tissue exclusively that had taken it. This color 

 was so sharp that it was possible to distinguish areas so small as to be otherwise 

 indistinguishable macroscopically. Microscopically from preparations or from 

 frozen sections ( prepared from the pancreas treated with the copper solution ) 

 it was ascertained that the normal fat cells contained no trace of blue, while the 

 necrotic areas were clearly blue green. The most intense color was in the 

 needle-shaped fatty acid crystals. Before embedding a counterstain may be used, 

 either alum or copper haematoxylin. The latter stain brings out some more 

 points. A section of the copper treated tissue is stained with an aqueous solu- 

 tion of crystalized haematoxylin and there comes, as in the Weigert process, a 

 blue black color, while the copper salt taken up goes over into a copper 

 haematoxylin. 



The fatty acid crystals, however, retain their blue green color. The author 

 thinks in consequence that the copper salt in the crystals cannot be merely 

 absorbed, but is present in some different chemical substance too firmly to be 

 displaced by ha;matoxylin. This must be a copper salt of the fatty acid. The 

 acids that are here concerned are stearic, palmitic, and oleic. The inner part 

 of the necrotic fat cell contains stearic and palmitic acids, while the outer 

 part of the cells contains a considerable amount of oleic acid. This new 

 reaction has several advantages for histological investigation. The other fat 

 staining methods, osmic acid and sudan-red, stain fats and fatty acids equally. 

 The sudan-red stain is extraordinarily adapted to show the parenchymatous 

 inflammation of the pancreas cells. But through the intensity of the staining of 

 the fat, the difference between the normal and necrotic cells disappears, since 

 the fatty acids, which are always surrounded by a fatty detritus, can scarcely be 



