1878.] 



The Magic Mirror of Japan. 



135 



has ever been employed in Japan to alter a portion of the surface in 

 such a way that this part becomes visible in the image formed by re- 

 flection, although invisible when looked at directly. A certain Tokio 

 mirror maker, however, said that he had employed the chemical 

 method for this purpose in the following way : — 



Coat the surface of the mirror with urushi (Japanese varnish), with 

 the exception of the portion that it is desired shall cast the brighter 

 reflection, then act on this part with a paste composed of equal parts 

 of sulphur and copper sulphate, powdered and mixed with shiro-umedzu 

 (white plum acid). If this paste, after being allowed to dry on the 

 mirror, which takes about two days, be rubbed off, and the mirror be 

 frequently polished, the pattern (so said this mirror maker) will 

 become invisible when looked at, but will appear in the reflection of 

 the mirror thrown on to a screen. If the above be true, then, if a 

 pattern be drawn on the face of the mirror with the varnish while the 

 remainder of the face is acted on chemically, this pattern should, on 

 reflection, appear darker than the rest. We therefore instructed him 

 to prepare two mirrors, and on the face of one to act chemically on a 

 portion corresponding with the letter " C," while, with respect to the 

 other, he was to leave untouched only a small part of the face, corre- 

 sponding with the letter "N." This he did; after several polishings 

 of the two mirrors both letters could be seen, either directly or on 

 reflection ; after many polishings, however, the letter " C" disappeared 

 for direct vision, but it also disappeared for reflection, and the letter 

 " N" remained visible, either if looked at very obliquely, or when a 

 bright light was reflected on to a screen. In other words, the attempt 

 of this mirror maker turned out a failure. He regards it as resulting 

 from a loss of his former skill, but we are inclined to think that he 

 was confusing the method with which he was acquainted for making 

 an image visible when the face of the mirror is looked at obliquely 

 (the phenomenon which is observed in the mirror at Kamakura), with 

 a method for making the so-called magic mirror, of which he has pro- 

 bably no knowledge. One very interesting fact, how r ever, came out in 

 this experiment, and that was the mirror on which the letter " C " was 

 made, and which did not originally reflect the pattern on the back, 

 acquired the power to do so after ten successive polishings. In fact, 

 the mirror maker caused this mirror to acquire the so-called magic 

 character, but in a way unexpected by himself. 



Explanations : — The possible explanations of the phenomenon shown 

 by certain Japanese mirrors may be divided into three classes : — 



1. The pattern might be scratched on the face of the mirror and 

 hidden by subsequent polishing. 



2. The portion of the face corresponding with the pattern might 

 have a different molecular constitution from the metal forming the 

 remainder of the mirror. 



l 2 



