372 HUMAN ANATOMY 



graphical anatomy. The method is also of value because Rontgen 

 pictures of the vessels injected with metal can be taken, and thus 

 we may determine their position without their being distended or 

 stretched. Recently quicksilver injections, on account of their simpler 

 technique, have been used a great deal for the taking of radiographs, 

 but displacement and distortion are not excluded. Further study will 

 determine what is best in each case. 



The injections of the blood-vessels of human bones recently carried 

 out by Lexer of Berlin, with a special technique, show that important 

 advances may be daily expected, as these injections have shown 

 certain points which were hitherto unknown to anatomy. Radio- 

 graphs of the same may be seen here in the German "Department of 

 Education." 



A procedure which is closely related to injection is corrosion. I 

 believe that corrosion following injections of metal was first carried 

 out by Bidloo. Hyrtl was recognized as the master of this method, 

 but in the hands of F. E. Schulze, Merkel, Schiefferdecker, Zondeck, 

 and others, striking results have been obtained in the anatomy of the 

 viscera, especially of the lungs and kidneys. 



The various procedures which are proposed to conserve the ma- 

 terial of human anatomy are more allied to chemistry. Here we may 

 consider the preparation of bodies for dissection, the conservation 

 of separate organs, the special methods of preparation, and finally 

 those for exhibition purposes in museums. Thus we may here dis- 

 tinguish between a preparatory technique, a special technique, and 

 a museum technique. We may add that these are different for macro- 

 scopic and microscopic anatomy. I cannot stop to mention all the 

 points in which anatomy must be grateful to physics and chemistry 

 in this connection, but shall only mention those which have been 

 recently developed. For the conservation of objects for investi- 

 gation the method of freezing has been used, especially in America. 

 France, and especially Russia, have made us familiar with the tech- 

 nique of frozen sections, which was raised to its highest point by 

 W. Braune. 



Recently in America simple hardening in strong formalin solution 

 has been used instead of freezing. I have seen here, with Professor 

 Potter of the St. Louis University, especially fine formalin specimens 

 and sections. 



The use of chemical methods has advanced us materially in the 

 art of macerating and bleaching bones. I will again recall in this 

 connection the anatomist of Krakau, Ludwig Teichmann, my teacher 

 in anatomy. The fibrillation procedure of Jacob Stilling of Strassburg, 

 which promises good results in the preparation of brains, nerves, and 

 muscles, also rests upon a chemical reaction. 



The technique of microscopic anatomy may also be considered as 



