In 1625, Sala pursued his research interests in conjunction with his service as the personal physician. His research and discoveries led to a better understanding of chemical reactions and the realisation that some substances are composed of chemical combinations of other substances. 
Sala's discovery of light-sensitivity of silver was advanced by other chemists before photography was finally achieved in the 1830s. 
Sala was above all a practitioner. In his view, demonstrations could be carried out only through manual operations (inventionibus manualibus), that is to say, only with the aid of experimental examples, which he clearly distinguished from argumentation. For him, chemistry was still a handcraft (ars).
The Carl von Ossietzky University Oldenburg annually awards students of northern German schools with the Angelus Sala Prize for the "Day of Chemistry", for those in the 10th class who have achieved outstanding academic achievements in chemistry.