Books can be attributed to "Anonymous" for several reasons:
* They are officially published under that name * They are traditional stories not attributed to a specific author * They are religious texts not generally attributed to a specific author
Books whose authorship is merely uncertain should be attributed to Unknown.
Maybe back in the day random illustration and random photos thrown in without a sense or style would make for a "visual" something. Today this would be an illustrated something.
The only way this is a dictionary, it is in the sense that it is a random collage of small blog posts. It is not complete. It is not well organized. It is not detailed.
Overall this volume can be interesting to see the evil medical guild consensus was back in the day, hence the second star.