On view

Along the walls of the museum is an overview of the collection’s 200-year history, the most important collectors and their respective collections. In particular this historical overview focuses on collections of pathological anatomy and animal morphology.

The body dissected
In Museum Vrolik – a collection that was amassed in the 19th century and the first quarter of the 20th century – the human body is the central focus. What do we look like on the inside? How are our organs and body parts structured and where exactly are they located? How are the muscles and blood vessels in your forearm arranged? Just how big are your auditory ossicles, the smallest bones in your body? And how is your neck bone connected to your head bone? 

Growth and development
The development of babies in the womb can be followed in detail at Museum Vrolik: from an embryo as small as a grain of salt to a full-term foetus. Other foetuses in spirits show how the developing brain acquires more and more grooves and folds. Development continues after birth: a series of jaws and skulls reveal the order in which teeth break through. Can you see how the new teeth are ready long before you start to lose your milk teeth?

Congenital defects
Congenital malformations are also on display in Museum Vrolik, such as a cyclopia and Siamese twins. They are the result of severe developmental defects; so severe that the children died shortly after birth. 
Fortunately many such anomalies have become rare in our Western world. The majority of problems are detected in the womb nowadays. This makes the Vrolik collection a valuable while at the same time moving legacy, and one which commands respect.

Hersenen met opgespoten bloedvaten
Siamese tweeling
Menselijk embryo in vlies


Diseased skeletons
Diseases that can be fought easily nowadays caused a lot of misery in the Amsterdam of father and son Vrolik. What diseases did people suffer from in the 18th and 19th centuries? In Museum Vrolik skeletons, skulls, individual bones and tens of specimens in spirits show the devastating effect of diseases such as rickets, tuberculosis and syphilis.

Anatomy of animals
The heart of a lion, the eye of a whale, the ovary of a chicken. Willem Vrolik was a particularly passionate collector of animal anatomy. To gain a better understanding of the ‘natural order’ in which – according to the Vroliks – all organisms had a place, it was important to carefully compare the organs of man and animals. By the way: they didn’t, believe in evolution. 
Only their successors took Darwin’s Evolution Theory as the starting point for their research and collection activities. They too added many animal skeletons, skulls and specimens – especially of monkeys and apes.

Door ziekten misvormde skeletten
Uilenkop en kameleon
Gorillaschedel

Techniques

'Strong water'
The collecting of human body parts has a long history. One example is the preservation of holy relics, which were supposedly the remains of saints. It is only since the Renaissance that body parts have also been collected for non-religious reasons.


Initially, mainly bones and skulls were collected. Drying was the only preservation technique known at the time, and this was more suited to bones than tissue and organs. Most of the body parts that were collected ended up in cabinets of curiosities.


From the 17th century, specimens were preserved in spirits, an art in which Amsterdam anatomist Frederik Ruysch (1638-1731) gained world renown. The 'strong water’ used for preservation was originally alcohol (c. 60%), but formalin was used from the end of the 19th century onwards. New conservation methods made it possible to prevent all kinds of tissue and organs from decaying. This meant that they could be studied in glass bottles and jars, year after year. 

Hand met dubbele duim
Menselijk oog met oogleden

Injecting
Ruysch also injected his specimens with a wax-like substance that he usually stained red. This substance penetrated the smallest of blood vessels. This method also gave his preparations a pinkish hue. Ruysch used the technique to make tissue structures more visible and so aid anatomical understanding. But the technique also made his preparations, of children's heads and hands for example, very lifelike. Ruysch heightened this effect by adding lace caps and cuffs. He also injected tissue and organs, which he then embalmed and dried.


The technique of injecting tissue with coloured wax-like substances continued to be used until the 19th century. Preparations of this type can also be found in the collection of Vrolik senior and junior, which includes both specimens in 'strong water' and dehydrated ones. Examples of organs in the Vrolik collection that have been injected with wax or dried include placentas and penises and, in particular, human and animal hearts. In order to make their anatomical structure more visible, in some cases one half of the heart was injected with red wax and the other half of the organ was injected with dark blue wax. The majority of the dry organ and tissue specimens were coated with shellac after drying.


The way in which specimens were preserved in jars and the method for sealing the jars hardly changed until the 19th century. Horse hair was used to suspend preparations in the jars, which were then sealed with a baffle plate, which was fixed at the edges with sealing wax. This was covered with a pig's bladder, which was then painted (usually red) when dry. The jars from the Vrolik collection that are still in their original condition can be recognised by the red seal. This also applies to the preparations in the Hovius-Bonn.collection. 

Aangekleurd weefsel van mens en dier
Dierenharten

Jars
All the jars and bottles that were used to collect the specimens in were round. Square jars did not become available until the end of the 19th century, during the professorship of the anatomist Georg Ruge . Square receptacles have an important advantage: the appearance of the specimens is no longer distorted by the rounded glass. Square jars were therefore particularly useful in teaching. From about 1900, most new specimens were kept in square jars – fixed in a frame or to a glass plate. Preparations that needed to be removed frequently for research or teaching in the 'cutting room' were kept in round apothecary jars. During this period, this resulted in a clearer distinction between the research collection, which was stored in a depot, and a museum collection that could be viewed by students and scholars. 
In the first decades of the 20th century, the clarity of the specimens was further improved under the supervision of the anatomist Lodewijk Bolk . His technique involved adding dark blue glass to the jar. The pale-coloured specimens stood out clearly against the dark blue background. In the modern-day museum, most of the preparations in the systematic part of the collection are in square glass vessels, and the sharp contrast between the preparation and the blue glass is immediately noticeable. 

Restoration

Between 2003 and 2010, almost the entire collection of wet specimens belonging to the museum was restored. The main aim was to preserve them in their original condition. Original labels, glassware and seals were preserved as far as possible. Specimens that had sunk to the bottom of their containers were suspended again. However, all specimens in formalin (c. 4%) were put into a new solution, Kaiserling III. This fluid consists mainly of glycerine, water and sodium acetate and is, in contrast to the 4% formalin solution, virtually harmless.