2 PROCEEDINGS OF THE ACADEMY OP [Biolog' 



February. 



I. Anatomy. 



Dr. Schmidt read the following paper upon a ' Method of Painting 

 moist Anatomical Preparations." 



Method of Painting- Moist Anatomical Preparations 

 BY II. D. SCHMIDT, M. D. 



it is more due to neglect than any other motive, that I have not pub- 

 lished, before this, the useful process of painting anatomical preparations, 

 intended to be suspended in alcohol. The latter, as is known to every 

 anatomist, affects the color of the different components of an organ, and 

 thus renders them almost alike in appearance. This is a great disadvan- 

 tage, as the object of such a preparation, is to show the relationship of 

 the various parts of an organ, or that of different organs themselves. 

 For instance, if the larger bloodvessels and ducts of a liver or kidney, &c, 

 are injected and carefully dissected out, to exhibit their relative course, 

 .such a preparation will be of comparatively little value, if these vessels 

 can not be readily distinguished from each other. This can only be ac- 

 complished by painting them with different colors. In dried preparations, 

 this is easily done by coloring with oil-paint, commonly used by artists. 

 But as the tissues of such preparations lose entirely their form by shrink- 

 ing, they are rendered to a great extent unfit for study. It is different 

 however, in the case of preparations intended to be preserved in a moist 

 condition by suspension in alcohol. Here, the anatomist often becomes 

 discouraged, when he finds his best dissections losing in appearance 

 by the injurious action of the alcohol on the color of the tissues. To 

 counterbalance this disadvantage, I have used a vehicle, which, while it 

 unites with the tissues and thus adheres to them, is not affected injurious- 

 ly by the action of the alcohol, but on the contrary, rendered only more 

 firm. The process is so simple, that it seems rather strange not to have 

 been resorted to long ago. The principle used as a vehicle, isalbumen, in 

 the form of the white of egg ; and this is almost the only substance which 

 will unite with the tissues, (as a great part of the latter consists of it,) 

 without being injuriously affected by the alcohol. The colors used, of 

 course must be mineral, and thoroughly ground with the albumen, on a 

 plate of glass. After the preparation is painted, it is put into strong 

 alcohol, which, to coagulate the albumen still more firmly, may be warmed. 

 Not only the blood-vessels, ducts and nerves, may thus be beautifully 

 colored, but with some artistical skill the color of the parenchyma of the 

 organ may also be nicely imitated. 



In the Anatomical Museum of the University of Pennsylvania, a liver 

 with the blood-vessels and ducts carefully dissected, and painted with 

 different colors by the above described process, can be seen suspended in 

 alcohol. Likewise a kidney and a spleen ; the color of the fresh 

 parenchyma of the former is also imitated. These preparations I made 

 three years ago, and up to the present time not the slightest change in 

 the colors can be perceived ; although they have often been carried to 

 and from the lecture room. Another preparation, exhibiting the smaller 

 muscles of the larynx, which are painted red, can also be seen. Intricate 

 dissections of various regions can be made, the muscles, vessels, nerves, 

 &c, colored, and their form preserved by the suspension in alcohol. 



[Feb, 



