Woodcut illustrating the 17th century text Xu Ping waike zhengzong (Orthodox Manual of External Medicine with Commentary by Xu Dachun), from an edition published in 1860 (10th year of the Xianfeng reign period of the Qing dynasty).
Right-hand illustration:
The image shows the disease location and appearance of the lesions known as 'Jade Pillow abscess' (yuzhen ju) and 'lesion opposite the heart' (duixin fa), and illustrates how these conditions are provoked by a stagnation of moist heat in the bladder. Jade Pillow abscesses are a type of abscess with a head or carbuncle, and are so called because they are found at the Jade Pillow point at the back of the head. The prognosis is excellent if they are red and inflamed, but poor if they are purplish black and sunken.
Left-hand illustration:
The image shows the disease location and appearance of the lesion known as 'Calamitous abscess' (yaoju). This is caused by a flare-up of Yang fire. The prognosis is excellent if the lesions are bright red, raised and inflamed, but poor if they are purplish black and depressed. Calamitous abscesses are discussed in the section on ulcers and abscesses of Lingshu (the Numinous Pivot, one of the two parts of the Yellow Emperor's Canon of Medicine, the most ancient and most famous extant work of Chinese medicine), where they are describing as occurring on the neck; this illustration shows them on the side of the neck and the back.