**Higher‑level collection that aggregates all sub‑directory holdings**

```cheimarros
@file_pinax -> describes -> @drexel_historical_medical_collections:collection {
    title: "Drexel University Historical Medical Collections",
    creator: @drexel_university,
    institution: @drexel_university,
    created: @date_1849,
    end: @date_1851,
    language: "en",
    subjects: [
        @medical_history,
        @nineteenth_century_medicine,
        @medical_education,
        @medical_theses,
        @historical_documents,
        @medical_instruments,
        @women_in_medicine,
        @homeopathic_medicine
    ],
    description: "A collection of 19th‑century medical materials—including theses, texts, images, and instrument documentation—held by Drexel University.",
    source: "PINAX",
    places: [@pennsylvania, @new_jersey, @new_york, @england, @scotland, @united_states, @philadelphia]
}
```

**Linking the four sub‑collections to the aggregate collection**

```cheimarros
@drexel_historical_medical_collections -> includes -> @ellis_collection_1851:concept
@drexel_historical_medical_collections -> includes -> @hunt_1851_collection:document
@drexel_historical_medical_collections -> includes -> @engle_thesis_collection:document
@drexel_historical_medical_collections -> includes -> @gardiner_thesis_collection:document
```

**Thematic concepts (newly defined for synthesis)**  

```cheimarros
@medical_history:concept {description: "Documents and scholarship concerning the development of medicine over time"}
@nineteenth_century_medicine:concept {description: "Medical knowledge, practice, and education in the 1800s"}
@medical_education:concept {description: "Training, curricula, and pedagogical materials for physicians"}
@medical_theses:concept {description: "Academic dissertations on medical topics"}
@historical_documents:concept {description: "Primary source materials of historical significance"}
@medical_instruments:concept {description: "Tools and devices used in medical diagnosis or treatment"}
@women_in_medicine:concept {description: "Women’s participation, advocacy, and representation in the medical profession"}
@homeopathic_medicine:concept {description: "Alternative medical system based on the principle of “like cures like”"}
```

**Geographic scope (reference common‑knowledge places)**  

```cheimarros
@philadelphia -> part_of -> @pennsylvania
@pennsylvania -> part_of -> @united_states
```

**Temporal and thematic synthesis across sub‑directories**

```cheimarros
# 1849 – Engle thesis (menstruation)
@engle_thesis_collection -> created on -> @date_1849_02_25
@engle_thesis_collection -> subject -> @women_in_medicine
@engle_thesis_collection -> subject -> @medical_education

# 1850 – Gardiner thesis (obstetrical forceps)
@gardiner_thesis_collection -> created on -> @date_1850
@gardiner_thesis_collection -> subject -> @medical_instruments
@gardiner_thesis_collection -> subject -> @medical_education

# 1851 – Hunt thesis (women in medicine)
@hunt_1851_collection -> created on -> @date_1851
@hunt_1851_collection -> subject -> @women_in_medicine
@hunt_1851_collection -> subject -> @medical_education

# 1851 – Ellis medical & historical images
@ellis_collection_1851 -> created on -> @date_1851
@ellis_collection_1851 -> subject -> @medical_history
@ellis_collection_1851 -> subject -> @nineteenth_century_medicine
```

**Cross‑collection patterns**

```cheimarros
# Women in medicine appears in both the Engle and Hunt collections, showing a recurring reformist agenda.
@women_in_medicine -> discussed in -> [@engle_thesis_collection, @hunt_1851_collection]

# Medical education is a shared focus of Engle, Hunt, and Gardiner collections.
@medical_education -> central to -> [@engle_thesis_collection, @hunt_1851_collection, @gardiner_thesis_collection]

# Medical instruments (obstetrical forceps) link Gardiner’s thesis to the broader instrument documentation in the Ellis image set.
@medical_instruments -> illustrated in -> @ellis_collection_1851
@medical_instruments -> examined in -> @gardiner_thesis_collection
```

**Institutional context**

```cheimarros
@drexel_university:organization -> holds -> @drexel_historical_medical_collections
@drexel_university -> located in -> @philadelphia
```

**Resulting synthesis**

- **Aggregate entity** `@drexel_historical_medical_collections` unifies four distinct 19th‑century medical collections.
- **Temporal chain** runs from Engle’s 1849 thesis, through Gardiner’s 1850 work, to the 1851 Hunt thesis and Ellis image set, illustrating the evolution of medical thought and documentation over a short period.
- **Thematic chains** reveal recurring emphases on *women in medicine*, *medical education*, and *medical instruments* across multiple collections, indicating a coherent scholarly focus within Drexel’s holdings.
- **Geographic breadth** spans the United States (Pennsylvania, New Jersey, New York) and the United Kingdom (England, Scotland), reflecting the trans‑Atlantic nature of 19th‑century medical discourse.