The following is some preliminary research into a few terms used by H. P. Blavatsky, which appear to be Chinese terms given in an archaic spelling.
First, it seems Blavatsky is sometimes using an old French system of transliteration from the Chinese, called the EFEO system (see also here). This is where we get the “tch” and “ts” beginnings from, where generally “tch” is the modern pinyin “zh” or “ch” and “ts” is the modern pinyin “z” or “c.” Also, in EFEO “s” can become pinyin “x” (as we find with “yih-sin” becoming “yīxīn”).
I also suspect Blavatsky was drawing often from French Sinologists for some of her info when dealing with Chinese terms, including and maybe especially works by Stanislas Julien, but also Jules de Mirville and others. It is difficult to wade through those French sources (including periodical magazines etc.) but it is in those that I am most often finding spellings that match Blavatsky’s, so this is a direction that needs in-depth exploration, and may help us solve some of the pesky terms many theosophists have been wondering about.
Now, to the terms I’ve been looking into:
In the Glossary, Blavatsky has the following:
Tsien-Sin (Chin.). The “Heaven of Mind,” Universal Ideation and Mahat, when applied to the plane of differentiation “Tien-Sin” (q.v.) when referring to the Absolute.
Tien-Sin (Chin.). Lit., “the heaven of mind,” or abstract, subjective, ideal heaven. A metaphysical term applied to the Absolute.
Tsien-Tchan (Ch.). The universe of form and matter.
Tien-Sin is undoubtedly 天心, tiānxīn, as we see here, the “mind of heaven” or “heaven of mind.” Tsien-Sin may be something slightly different (see below), as Blavatsky makes a distinction between the two spellings. Note also that in Isis, 2:286 Blavatsky used the spelling “zion” for Buddhist “heavens”; “zion” here may perhaps refer also to the spelling “tsien” rather than to the common “tien” or “tiān.” The use of “z” might be somewhat valid, as we see that in EFEO transliteration “ts” stands for “z” in pinyin. This is also shown in the next term in the Glossary:
Tsi-tsai (Chin.). The “Self-Existent” or the “Unknown Darkness”, the root of Wuliang Sheu, “Boundless Age”, all Kabbalistic terms, which were used in China ages before the Hebrew Kabbalists adopted them, borrowing them from Chaldea and Egypt.
So here we have “ts” as “z,” as we would expect from an EFEO transliteration. This may thus also be the case with “tsien” (but there are other possibilities I’ll explore below).
So in the second term “Tsien-Tchan,” the first part is almost certainly also directly related to 天 tiān, “heaven” with perhaps two spellings.
Reference links, before getting into details:
I was told by a Chinese linguist that Tsien-tchan is almost certainly 天下 tiānxià, which means “all that is under heaven” and philosophically signifies the manifested universe.
天下 tiānxià: land under heaven; the whole world; the whole of China; realm; rule (see here, click the double-arrow where you can listen to the pronunciation)
The IPA (modern) pronunciation is /tʰjɛn ɕjä/ Try it here: http://ipa-reader.xyz
“The term tian simultaneously refers to the sky, the orderly movement of the heavens, and something that covers all things equally. The classical Chinese word for the “world” or “realm” is literally what is “under-heaven,” tianxia 天下.” source: https://plato.stanford.edu/entries/chinese-metaphysics/
So this fits quite well both in meaning and in pronunciation (excepting no clear final “n”), though it doesn’t strictly follow the EFEO system, where “tch” ought to be “zh” or “ch” and “h” or “s” would be “x.”
Another, similar case, from the writings of H.P.B. may support her use of a final “n” where none exists in the Chinese, this being the name of the 6th Patriarch as given in her book The Voice of the Silence, Fragment 2, Note 6. There she spells the name Shin-Sien where in Hanyu pinyin it is Shénxiù (神秀). The final character 秀 (xiù) carries a similar pronunciation as “sien,” but minus the closing “n” sound. It may be, then, that in our current case, “tchan” similarly becomes 下 (xià), again with the same pronunciation, minus the closing “n.”
The main issue with the spelling “tchan” is that the transliteration can be used for multiple Chinese words/characters and seems to have been used outside of the strict EFEO system. For instance, see all these examples of the spelling “tchan” here, here, here, here, here, and here, each standing for a different Chinese word with different beginning letters in pinyin.
Other possibilities to get out of the way for now:
Another related term is 天山 tiānshān, the “heavenly mountain,” which connects with the Hindu idea of mount Meru and has a similar pronunciation (see it spelled as “tien-chan” here, for instance).
You’ll also find a term spelled “tien chan” in some places, meaning “celestial empire” (see here and here, for examples), which term is 天朝 tiāncháo (note this is also commonly spelled with a final “n” though there is no “n” sound, which may lend support to “xia” instead of “tchan,” also without the final “n” sound.
While these last two share similar pronunciations and relatively connected meanings, I do think that tiānxià is more likely in the right direction, as it is philosophically exactly what Blavatsky says it is, “the universe of form and matter.”
With all that said, here’s something further from an old French-Chinese dictionary:
The Chinese above is 先估者 xiān-gū-zhě, but seems to be slightly mistaken, and should be 先佔者 xiān-zhàn-zhě (估 and 佔 obviously looking very similar). So this gives us the term “xiān-zhàn,” literally “the first occupied” or “the first taken possession of.” (source)
If we take Blavatsky’s most common spelling of “sien-tchan” (without the first “t”), this follows the EFEO exactly, where we have “sien” becoming “xian” and “tchan” becoming “zhan.” It also fits with the English words Blavatsky uses with the Würzburg MS spelling of “sien-tchen,” i.e. “one universe,” (p. 207) since xiān means “first.”
This may also give us the distinction we were looking for above, where we have two terms with related meanings: “Tsien-Sin” (or Sien-Sin?) and “Tien-Sin,” which would thus be 先心 xiānxīn, the “first mind,” and 天心, tiānxīn, the “heaven of mind.” Xiānxīn (“first mind”) would be perhaps closely synonymous to 一心 yīxīn, the “one mind,” which is Blavatsky’s “yin sin” or “yih sin.” This would match the distinctions Blavatsky makes in the Proem between the “first cause” and the “absolute,” so 天心, tiānxīn would correspond to the Absolute per se and 先心 xiānxīn to the First Logos, or put another way: Mahat unmanifested (merged in the absolute) and Mahat manifested.
In the same way, perhaps we would also have a distinction in the second term “Tsien-Tchan” or “Sien-Tchan” (先佔 xiānzhàn, the “first occupied (world)” (first manifested plane or the “archetypal world” of SD 1:200?) and “Tien-Tchan” (天佔 tiānzhàn (“occupied heaven” (?), the three higher “arupa” planes on SD 1:200?). But in this case, our earlier term, 天下 tiānxià, would connect in meaning to xiānzhàn rather than tiānzhàn.
This is all speculative and preliminary, of course, but perhaps heading in the right direction. At the very least, I do think a case can be made that “tsien-tchan” is likely indeed a Chinese word and not a Tibetan one as some of us have speculated on (i.e. the Tibetan “sems can”). The next step in this research will be to search for instances of the above terms in ancient texts with at least a somewhat similar meaning as Blavatsky ascribes. This will be extremely difficult, of course, as most Chinese texts aren’t easily accessible by non-Chinese speakers, and most are as yet untranslated.
We also have to address the difficulty in the phrase “Yinsin in night of Sun-chan” on SD 1:23. It is possible that “sun” was a mistaken reading from Blavatsky’s handwriting, instead of “sien” (anyone who’s looked at her handwriting knows how tricky it can be, and “ie” does sometimes look indistinguishable from “u.” “Sien-chan” matches what we find on CW XIV:408fn (SD 3:393), thus: “The Universe of Brahmā (Sien-Chan; Nam-Kha) is Universal Illusion, or our phenomenal world.” If in the SD, Sien-chan was meant, we would have the phrase “yihsin in night of sien-chan” or “sien-tchan” (?), which may thus be: 一心 yīxīn (the “one mind”) in night of 先佔 xiānzhàn (the “first occupied (world)”), which conceptually fits with the state wherein the 4 “rupa” planes are withdrawn into the 3 “arupa” planes (see SD 1:200).
Next, in the SD (2:365) Blavatsky says:
“Our races—they all show—have sprung from divine races, by whatever name they are called. Whether we deal with the Indian Rishis or Pitris; with the Chinese Chim-nang and Tchan-gy—their “divine man” and demi-gods”
This is drawn from deMirville, Des Esprits, vol. 3, p. 40:
“Nous avons déjà vu que dans les Kings de la Chine les dix Ki (ou patriarches) ne faisaient qu’un avec leurs Chin-non ou Tchang-y, dieux ou demi-dieux, suivant leur plus ou moins d’elevation hierarchique . . .”
The connection to “divine man” and “demi-gods” seems to be an interpretation based on the genealogies of the sovereigns/emperors, in much the same way as we see with the Rishis, Prajapatis, Patriarchs, etc. in Blavatsky’s writings.
As we see here, this instance of “tchan” in the SD isn’t actually “tchan” but rather “tchang,” and is thus not the same Chinese word as in “Tsien-Tchan.” And in this case the letters “tch” become “ch” in pinyin.
A possible related term to “chāngyì” is 神祇 shénqí (“gods, earth spirits”). This relates directly to the idea of “demi-gods,” though I’m unsure if there’s any relation to the geneologies of emperors and the name chāngyì.
This is the extent of my current research. All this requires further investigation and substantiation in extant Chinese texts, but may perhaps be a step in the right direction.