1894.] 3IICR0SC0PICAL JOURNAL. 179 



Is the Paraffin Imbedding Method Better Than the 

 Celloidin ? 



Bv PHILIP JAISOHN, M. D., 

 Denionattator of Histology iu Medical Department of Columbian University. 



Before discussing tlie respective merits and demerits 

 of each method, it is necessary to describe briefly the 

 technic[ue of both, iu order to discuss them intelligently, 



The paraffin method was first used by Fredericq, and 

 described by Schwalbe in 1886. (Anatomischen Anzei- 

 ger). Subsequently, Wm. C. Krauss described more 

 fully with some modifications, in 1888. (Fortschrittz 

 der Medicin, 1888, No. 16). The method is as follows : 



Put the fresh tissue first in 75 per cent alcohol, and keep 

 it there for 24 hours; transfer it to 95 per cent alcohol, 

 and let it remain for 24 hours ; then again in absolute 

 alcohol for the same length of time. Remove the alco- 

 hol from the tissue by soaking it in pure chloroform for 

 24 hours ; transfer it to melted paraffin mixed with equal 

 quantity of chloroform, leave it in this for 24 hours ;then 

 change to pure melted paraffin. After 24 hours or 36 

 hours, imbed the tissue in a paper box or metalic mould 

 with paraffin round it. It hardens in 15 or 20 minutes, 

 and is ready to cut. 



To stain the paraffin sections, the paraffin in the tissue 

 must be dissolved by oil of turpentine and then remove 

 the turpentine by dropping the sections in 95 per cent 

 or absolute alcohol, then to water, and the stain. Abso- 

 lute alcohol is used to dehydrate the sections- and the 

 clearing agents generally used are turpentine or oil of 

 clove. Celloidin method was first introduced by Duval 

 in 1879. {Journal de Vanat. et de la physioL T. XV.) 

 Subsequently employed and described by P. Schieffer- 

 dectes {Archiv. f. anat. u. Physiol. 1882). This method 

 has but one point in common with the paraffin process: 

 the tissue is infiltrated with the imbedding mass ; the 



