In 1812, Georg Sachs published a medical dissertation concerning his own albinism and that of his sister. However, he also goes on to describe another phenomenon--namely synaesthesia involving colors for music and simple sequences (including numbers, days, and letters). Most contemporary researchers of synaesthesia fail to cite the case when offering a history of the subject and fewer still will have read it (the original was published in Latin). In this article, we argue that Sachs's case is the first convincing account of synaesthesia; we provide the first English translation of his description of it; we discuss the influence of the case in early theories about synaesthesia and its resonance with contemporary research findings.

The first case of synesthesia was reported in 1812 ( Jewanski, Day, & Ward, 2009 ). However, it took almost seven decades before the idea of synesthesia entered the mainstream of science and, subsequently, art. There are no known new cases described between 1812 and 1848, but in the following three decades there are at least 11 reported cases of synesthesia and many reviews of these cases. This comes at an important period in the history of the neurosciences, and for sensory physiology in particular. However, the literature that describes synesthesia during this period is largely unknown to contemporary researchers and historians. The aim of this review is to discuss the reports of synesthesia during this period, providing translations of some key passages, and to place these reports within the contextual framework of nineteenth-century neuroscience.

Synesthesia is a rare neurological trait that causes unusual, often crosssensory, experiences (e.g., seeing colors when listening to music). This article traces the history of synesthesia in the period 1876 to 1895. In this period, there was considerable debate over the nature of synesthesia, its causes, and how it should be named. The issue also attracted the leading thinkers of the time and, within a few years, the number of reported cases of synesthesia jumped from around ten to more than 100. For this reason, this period can be regarded as the "golden age" for synesthesia research in the nineteenth century. In this time, scientists debated whether synesthesia was a form of pathology or an alternative manifestation of intelligence. The differing roles of heredity and environment were contested, and there were several explanations proposed as to its neural basis. These enquiries went to the heart of the debate as to whether synesthetic experiences are special in any way or, instead, a more vivid manifestation of a more general capacity for forming associations.