What are picture transformation books [blow books]? The historical roots of picture transformation books can be traced back almost 500 years to the early 16th century. They are first-grade rarissima and are among the most rarely found and most fantastical types of book known to us today. Worldwide, only four hand-painted copies dating from earlier than 1750 are known to exist - either in libraries or private collections. This may be the reason why they have remained almost unnoticed by book and manuscript researchers and have not therefore been the subject of adequate academic research. The planned publication Magic Metamorphosis - The Secrets of a Rare Italian Picture Album Revealed aims to close this gap in research. How does a blow book work? A transformation or blow book is a kind of trick book composed of repeated sequences of pictures that allow an optical illusion or facilitate the performance of an amazing magic trick. To this end, index with several tabs or indentations, almost invisible from a distance, is cut along the fore-edge of the volume. Each of these tabs correlates with a very specifi c pictorial motif. When leafi ng through the transformation book, the performer can precisely grasp one of the tabs with his thumb and thus show the audience a desired picture motif or make it disappear again. Several pages are unpainted, so that the blow book can also made to be seemingly empty - a magical eff ect. As early as the 17th century, it was customary for the magician to have a spectator blow on the transformation book during the performance - a kind of magical gesture. The term blow book, which is most commonly used in English-speaking countries today, can be traced back to this gesture. Where were blow books presented historically? In historical times, this trick was performed as part of a magic show for all social classes: on festive occasions in royal and princely houses, at the soirées so popular in aristocratic circles, at fairs, exhibitions, in pubs and inns or on the street. What is the significance of blow books for cultural history? The importance of blow books within cultural history is repeatedly documented by numerous mentions in historical sources. In his memoirs, the Indian imperial mogul Jahangir (1569-1627) reports enthusiastically about the performance of this magical transformation at his court. In his novel Der Seltzame Springinsfeld, the famous German writer and Baroque poet Hans Jakob Christoph von Grimmelshausen (1622-1676) also made the blow book the subject of his story no less than three times, describing it in all its facets over an entire eleven pages. The blow book even found its way into specialised mathematics and physics volumes: for example, in the works of the two famous polymaths Athanasius Kircher (1602-1680) and Caspar Schott (1608-1666) it is mentioned as a mechanical fascination. Today, blow books are also available on the book market for children - as a kind of educational tool for practising presentation and speaking skills. What was the motivation behind this research into blow books? This research was given impetus by a globally unique picture album (Disegni Antichi Bizzarri) produced in Italy at around 1650 and discovered by the author Thomas Stauss in Paris at the end of the 1990s: although this picture album was lacking index, it was clearly identifiable as a picture transformation, or blow book. In 2018, fortuitous circumstances enabled the author to fi nally acquire this rare object for his collection and he has been researching it intensively ever since. Of particular signifi cance for the analysis of this album was and is its historical connection to the history of Swiss natural science. The artist used the famous work Historia animalium by the Zurich natural scientist and physician Conrad Gessner (1516-1565) as a reference or model book for the depiction of the animals, fi sh and birds presented in the album. Almost 40 per cent of all the illustrations in the album are based on Gessners work, which was the foundation of modern zoology as we know it today. The planned publication will contain all the research results and fi ndings from the analysis and examination of the picture album. These are to be published in two volumes (including slipcase): Facsimile of the original Disegni Antichi Bizzarri picture album (including index to demonstrate and illustrate its function as a blow book) Explanatory volume