“The possibility of reading the contents of documents inclosed in a sealed envelope,” he replied, still studying the shadowgraph closely, “has already been established by the well-known English scientist, Doctor Hall Edwards. He has been experimenting with the method of using X-rays recently discovered by a German scientist, by which radiographs of very thin substances, such as a sheet of paper, a leaf, an insect’s body, may be obtained. These thin substances through which the rays used formerly to pass without leaving an impression, can now be radiographed.”
I looked carefully as he traced out something on the negative. On it was easily possible, following his guidance, to read the words inscribed on the sheet of paper inside. So admirably defined were all the details that even the gum on the envelope and the edges of the sheet of paper inside the envelope could be distinguished.
“Any letter written with ink having a mineral basis can be radiographed,” added Craig. “Even when the sheet is folded in the usual way, it is possible by taking a radiograph stereoscopically, to distinguish the writing, every detail standing out in relief. Besides, it can be greatly magnified, which aids in deciphering it if it is indistinct or jumbled up. Some of it looks like mirror writing. Ah,” he added, “here’s something interesting!”
Together we managed to trace out the contents of several paragraphs, of which the significant parts were as follows:
I am expecting that my friend Señora Herreria will be in New York by the time you receive this, and should she call on you, I know you will accord her every courtesy. She has been in Mexico City for a few days, having just returned from Mitla, where she met Professor Northrop. It is rumored that Professor Northrop has succeeded in smuggling out of the country a very important stone bearing an inscription which, I understand, is of more than ordinary interest. I do not know anything definite about it, as Señora Herreria is very reticent on the matter, but depend on you to find out if possible and let me know of it.
According to the rumors and the statements of the señora, it seems that Northrop has taken an unfair advantage of the situation down in Oaxaca, and I suppose she and others who know about the inscription feel that it is really the possession of the government.
You will find that the señora is an accomplished antiquarian and scholar. Like many others down here just now, she has a high regard for the Japanese. As you know, there exists a natural sympathy between some Mexicans and Japanese, owing to what is believed to be a common origin of the two races.
In spite of the assertions of many to the contrary, there is little doubt left in the minds of students that the Indian races which have peopled Mexico were of Mongolian stock. Many words in some dialects are easily understood by Chinese immigrants. A secretary of the Japanese legation here was able recently to decipher old Mixtec inscriptions found in the ruins of Mitla.
Señora Herreria has been much interested in establishing the relationship and, I understand, is acquainted with a Japanese curio dealer in New York who recently visited Mexico for the same purpose. I believe that she wishes to collaborate with him on a monograph on the subject, which is expected to have a powerful effect on the public opinion both here and at Tokyo.
In regard to the inscription which Northrop has taken with him, I rely on you to keep me informed. There seems to be a great deal of mystery connected with it, and I am simply hazarding a guess as to its nature. If it should prove to be something which might interest either the Japanese or ourselves, you can see how important it may be, especially in view of the forthcoming mission of General Francisco to Tokyo.