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Histology. — "A method of cohl uijccllou of on/an-s for histolo(jical 

 />itrpos('s'\ By Prof. 11. .1. Hamburger. 



Foi' a I'onsidenihle tiiiie tlie want has been felt of rephicing- at 

 injections for hislologieal pnrposes the warm substance, for which as 

 a rule stained gelatine was taken, by a cohl one; nol only becanse 

 when using a warm mass the technical difficulties, which are great 

 already, are rendereil more complicated still, owing to the care neces- 

 sary to keep organ and mass at bodily temperature, but also because 

 in a warm waterbath the structure of the tissues is frequently im- 

 paired. Therefore Taguchi proposed in 1888^) to use for this purpose 

 a suspension of Japanese Indian ink iji water, but Grosser -) pointed 

 out as a drawback that on further treatment of the sections the 

 isolated grains not seldom drop, if not out of the smaller yet out oi' 

 the larger vessels; whilst already at the cutting they are not seldom 

 dispersed over the surface of the section. He therefore tried to find 

 a fluid which could easily be solidified after the injection and found 

 that the white of a hen's egg cut and afterwards filtrated answered 

 this purpose very well. 



When we too wished to apply this method the difficulty made 

 itself felt, that in this manner we could not obtain the mass in a 

 sufKiciently fluid state. When according to the prescription we rubbed 

 the piece of Indian ink over the plate of ground glass a membrane 

 was always formed. Moreover it was found that the suspension thus 

 prepared, when kept in a bottle, had become a solid mass after 24 

 hours, although evaporation was out of the question. 



Probably this had to be attributed to the Indian ink of which, as 

 is wellknown, many kinds are found in the trade. But we did not 

 succeed in getting a better one. 



We then tried to obviate this difficulty by mixing the egg white 

 solut'ion with li(/iiid Indian ink as is to be obtained in the trade 

 under the name of GüNTHER-WAGNER'sche flüssige Perltusche, in the 

 volumetric proportion of 1 to 1. The result was a thin liquid mass, 

 which, when examined under the microscope, contained only exti-e- 

 mely small particles, which were in Brown's molecular motion. 



After injection with this fluid the organ was fixed in sublimate- 

 formol by which the injected egg white could be precipitated. After 

 the usual washing with water containing iodine, pieces of the organs 

 were stained with alumcochineal, and afterwards embedded in paraffin 



1) Archiv. f. Mikrosk. Anatomie, 31, p. 565, 1888. 



2) Zeitschr. f, Wissenschaftliche Mikroskopie, 17, p. 187, 1900. 



