Noble Heath, A Treatise on Arithmetic, 1856
The following excerpt is from the book A Treatise on Arithmetic : Through which the Entire Science Can be Most Expeditiously and Perfectly Learned, Without the Aid of Teachers by Noble Heath, published in 1856 and copyrighted in 1855.
The portion quoted here concerns the "Chuquet" numbernames.
These numbernames have long since been supplanted by the ConwayWechsler system, see full list of individual "zillions".
This book was referenced by W. D. Henkle in Names of the Periods in Numeration, 1860.
SECTION II.
NUMERATION.
38. Numeration is the general method of reading and writing numbers.
39. As there is no end to the formation of new orders on the left, and as it would, even in ordinary numbers, be inconvenient to give a new name to each new order, the figures of large numbers are separated into periods of three figures each. Thus beginning at the right hand, and proceeding towards the left we separate, by a comma, the first three figures, which constitute the first period. Then, proceeding towards the left, we separate three more, and so on, regularly, till the whole of the figures are thus separated. As the number may consist of any number of figures, it is evident that the lefthand period will often contain only one or two figures.
40. The first or right hand period is called Units; the next Thousands; the next Millions; and so, in succession, Billions, Trillions, Quadrillions, Quintillions, Sextillions, Septillions, Octillions, Nonillions, Decillions, Undecillions, Duodecillions, Tredecillions, Quatuordecillions, Quindecillions, Sexdecillions, Septendecillions, Octodecillions, Novendecillions, Vigintillions, Vigintiunillions, Vigintibillions, &c.
41. To facilitate the remembrance of the names of the periods, to show their import and relative position in the scale of numbers, as well as to extend them as far as required by any number within the scope of human thought or calculation, the following Table of Latin Numerals, from which they are nearly all derived, will be found very useful.
From this Table we also derive the names of some months; and there is this singularly coincident irregularity, viz., as the Romans began their year in March, the month September was, as its name denotes, in their Calendar, the Seventh; whereas, in ours, — to which the name has been transferred, and which begins two months earlier, — it is the Ninth; so, also, in the scale of the periods, as we have two names, Units and Thousands, which do not belong to the regular nomenclature, in which we may suppose that the name Millions been substituted for Unillions; the period Billions, which, from the import of the word, should be the second, is the fourth, and, consequently, Septillions, which should be the seventh, is the ninth period.
42. To correct this discrepance, therefore, we must, in applying the Table, add 2 to the number corresponding to the name of the period, (or month,) which will give its order; or subtract 2 from the number showing its order, which will give the number corresponding to its name. Thus, for exampie, if I would know the order of the period Octillions or the month October; as octo is eight, I add 2, which makes 10; I therefore say that Octillions is the tenth period, and October, the tenth month.
43. Again : if I wish to know the name of the twelfth period, I subtract 2 from 12, and I have 10; which, in Latin, is decem : I therefore say, that the name of the twelfth period is Decillions.

44. By means of the table we may continue the nomenclature of periods, thus: vigintitrillions, &c. to vigintinonillions; trigintillions; trigintaunillions, triginlabillions, &c.; quadragentillions; quadragintaunillions, &c.; quinquagentillions; sexagentillions; septuagentillions; octogentillions; nonagentillions; centillions.
45. The above Table, as well as the names of the periods in the Scale of Numbers, we could easily extend, but such extension could, for our present purpose, be of no utility; seeing that the number 1 centillion is far above the scope of human affairs or conception. For, if we suppose a hollow globe, ten millions of millions (10 trillions) of miles in diameter, to be filled with dust, so fine that there should be one thousand millions (1 billion) of particles in each cubic inch; the whole number of particles in this mighty mass would be an inconceivably small part of a centillion.
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