The Philosophical Transactions of the Royal Society was founded in 1665 by Henry Oldenburg. This article analyzes the domains of study and most frequent genres present in the items published in the year 1675. This provides part of the background necessary for the understanding of these scientific texts from a former period. The fields most frequently encountered are those of astronomy and physics. The subjects treated in the domain of astronomy are dependent on the celestial events that took place that year. Those in the area of physics are determined by the interests of a few eminent scientists such as Robert Boyle and Denis Papin. The incidence of agricultural items is due to the intellectual heritage of Francis Bacon. Less frequent are the areas of medicine, biology, botany, and geography. Among the less common fields, such as geology and technology, items concerning watches are significant, because of their importance to solving the longitude problem. Fields covered uniquely by book reviews, such as language, economics, and architecture, are more marginal to the interests of the journal’s readership.