"Allow me to inform you that there are no stuffed animals in this house" Waterton declared to a visitor to his museum in 1856.  

He went on to demonstrate that his specimens were all hollow by pulling off the head of a preserved polecat and revealing that there was nothing inside.  

Waterton's unusual method relied on the use of the chemical Mercuric Chloride which both prevented insect attack and set the skin hard.  

He began the process by scraping away much of the inside of the skin. He then set up the animal roughly into the correct position.  

Progressively he returned to the specimen each day, making minor adjustments until he considered that it was sufficiently lifelike.  

As far as it is possible to judge, Waterton's specimens do appear to have been better than others preserved in the nineteenth century.

He certainly believed it to be so.  

He particularly stressed that you should observe the live bird carefully to ensure the stance or form of the museum specimen was correct.   Unfortunately his method was difficult and slow and it has seldom been copied.