| 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.