Canopus, the second-brightest star in the southern hemisphere, served as a southern pole star for travelers in the northern hemisphere until magnetic compasses became common. Depicted on a map found in Dunhuang, Gansu province, believed to be from the reign of Emperor Zhongzong (r. 705-710) of the Tang dynasty, Canopus is part of a nine-star constellation (Gan Shi or Tian Pu) representing the garden where Shoulao grew his herbs of longevity (xian cao).
This bottle falls into a group of agate bottles where the variations in color in the stone provide all or part of the design, with or without surface editing. In a lecture before the 1996 ICSBS convention in Hong Kong, Hugh Moss proposed the term "ink-play" to relate the adaptation of principles of ink painting to particolored chalcedony (reproduced JICSBS, Autumn 1997, pp. 4-16). "Ink-play" in the painting tradition refers to the interpretation of random markings made by the free expression of the artist's brush, ink, water and surface. With respect to hardstone carvings, this effect is achieved firstly by reading the markings as representational imagery, and secondly, by achieving a balance between the natural markings and subsequent enhancements by the artist. See Moss, Graham and Tsang, A Treasury of Chinese Snuff Bottles, Vol. 2, Quartz, no. 274 for further discussion of this genre of snuff bottles.
The present bottle is an excellent example of this art form, where the artist has created the figure of Shoulao from the natural brown coloring of the stone by the addition of simple incised lines. The restraint of the design is in harmony with the Daoist subject. See also, Moss, Graham and Tsang, Quartz, no. 275, for a similar "ink-play" bottle inscribed with an auspicious wish.