MM. CHAMPION AND PELLET (Industries de l’empire Chinois, p. 64) give the following composition for Chinese mirrors:
| Copper | 50·8 |
| Tin | 16·5 |
| Zinc | 30·5 |
| Lead | 2·2 |
| ——— | |
| 100·0 | |
| ——— |
Dr. Geerts gives (Trans. Asiatic Soc. of Japan, vol. iv., p. 40), for the alloy used in one of the largest mirror-foundries in Kioto:
| Copper | 80 |
| Tin | 15 |
| Lead | 5 |
| —— | |
| 100 | |
| —— |
And for mirrors of inferior quality:
| Copper | 80 |
| Lead | 10 |
| Shirome | 10 |
| —— | |
| 100 | |
| —— |
Shirome is a natural sulphide of lead and antimony from Choshiu or Iyo.
Professors Ayrton and Perry (Proc. Roy. Soc., 1878) give:
For mirrors of first quality:
| Copper | 75·2 |
| Tin | 22·6 |
| Iyo Shirome | 2·2 |
| ——— | |
| 100·0 | |
| ——— |
For mirrors of second quality:
| Copper | 81·3 |
| Tin | 16·3 |
| Iyo Shirome | 2·4 |
| ——— | |
| 100·0 | |
| ——— |
For mirrors of third quality:
| Copper | 87·0 |
| Tin | 8·7 |
| Iyo Shirome | 4·3 |
| ——— | |
| 100·0 | |
| ——— |
For mirrors of fourth quality:
| Copper | 81·3 |
| Tori Shirome | 16·3 |
| Iyo Shirome | 2·4 |
| ——— | |
| 100·0 | |
| ——— |
For mirrors of fifth quality:
| Copper | 71·5 |
| Tori Shirome | 28·5 |
| ——— | |
| 100·0 | |
| ——— |
The mercurial amalgam used in polishing the mirrors consists, according to Dr. Geerts (op. cit.), of quicksilver, tin, and a little lead. Ayrton gives it as one of tin to one of quicksilver. Champion and Pellet (op. cit.) give the composition as:
| Tin | 69·36 |
| Mercury | 30·0 |
| Lead | 0·64 |
| ——— | |
| 100·00 | |
| ——— |
On the occasion of the delivery of this discourse the Author exhibited a collection of thirty-four Japanese mirrors, and by the aid of a lime-light lantern displayed their magic properties upon a translucent screen. He also exhibited sundry experiments with Laurent’s apparatus, and showed the effect of heating mirrors.