As set out in McLuhan reads Innis (PEMS 1), Innis cited Edward Bulwer and Thomas Carlyle on the world-changing event of Gutenberg in their writings in 1833 and 1834 respectively.¹ Bulwer at least must have obtained the idea from Victor Hugo’s The Hunchback of Notre Dame which appeared in 1831 and which Bulwer and his brother, Henri, both mentioned in their writings in the 1830s.

Innis went back from Bulwer to read Hugo’s account for himself and was immensely influenced by it.² Here are the relevant portions of Hugo’s long expository chapter (Hunchback, Book 5, Chapter 2):

We pause for a moment to seek what could have been the thought concealed beneath those enigmatic words of the archdeacon [earlier in the novel]: “This will kill that.³ The book will kill the edifice.”
To our mind, this thought had two faces. In the first place, it was a priestly thought. It was the fright of the priest in the presence of a new agent, the printing press. It was the terror and dazzled amazement of the men of the sanctuary, in the presence of the luminous press of Gutenberg.⁴ It was the pulpit and the manuscript taking the alarm at the printed word (…) the cry of the prophet who already hears emancipated humanity roaring and swarming; who beholds in the future, intelligence sapping faith, opinion dethroning belief, the world shaking off Rome. It was the prognostication of the philosopher who sees (…)  that one power was about to succeed another power. It meant, “The press will kill the church.”
But underlying this thought, the first and most simple one, no doubt, there was in our opinion another, newer one, a corollary of the first, less easy to perceive and more easy to contest, a view as philosophical and belonging no longer to the priest alone but to the savant and the artist. It was a presentiment that human thought, in changing its form, was about to change its mode of expression; that the dominant idea of each generation would no longer be written with the same matter, and in the same manner; that the book of stone, so solid and so durable, was about to make way for the book of paper, more solid and still more durable [yet]. In this connection the archdeacon’s vague formula had a second sense. It meant, “Printing will kill architecture.”
In fact, from the origin of things down to the fifteenth century of the Christian era, inclusive, architecture is the great book of humanity, the principal expression of man in his different stages of development, either as a force or as an intelligence.
When the memory of the first races felt itself overloaded,⁵ when the mass of [spoken] reminiscences of the human race became so heavy and so confused that speech, naked and flying, ran the risk of losing them on the way, men transcribed them on the soil⁶ in a manner which was [then] at once the most visible, most durable, and most natural.
(…)
The generating idea, the word, was not only at the foundation of all these [stone] edifices, but also in the form. The temple of Solomon, for example, was (…) the holy book itself.
(…)
Thought written in stone [was] a privilege exactly comparable to our present liberty of the press.
(…)
Thus, down to the time of Gutenberg, architecture is the principal writing, the universal writing.
(…)
In the fifteenth century everything changes. Human thought discovers a mode of perpetuating itself, not only more durable and more resisting than architecture, but still more simple and easy. Architecture is dethroned. Gutenberg’s letters of lead [type] are about to supersede Orpheus’s letters of stone. The book is about to kill the edifice.
The invention of printing is the greatest event in history. It is the mother of revolution (…) it is human thought stripping off one form and donning another; it is the complete and definitive change of skin of that symbolical serpent which since the days of Adam has represented intelligence.
In its printed form, thought is more imperishable than ever; it is volatile, irresistible, indestructible. It is mingled with the air. In the days of architecture it made a mountain of itself, and took powerful possession of a century and a place. Now it converts itself into a flock of birds, scatters itself to the four winds, and occupies all points of air and space at once. We repeat, who does not perceive that in this form [thought] is far more indelible [than in stone]? It was solid, [now] it has become alive. It passes from duration in time to immortality. One can demolish a mass; but can one extirpate ubiquity?
(…)
Before the invention of printing, reform [of the Church] would have been merely a schism; printing converted it into a revolution. Take away the press; heresy is enervated. Whether it be Providence or Fate, Gutenberg is the precursor of Luther.⁷
(…)
Thus, to sum up what we have hitherto said, in a fashion which is necessarily incomplete and mutilated, the human race has two books, two registers, two testaments: masonry and printing; the Bible of stone and the Bible of paper. No doubt, when one contemplates these two Bibles, laid so broadly open in the centuries, it is permissible to regret the visible majesty of the writing of granite, those gigantic alphabets formulated in colonnades, in pylons, in obelisks, those sorts of human mountains which cover the world and the past, from the pyramid to the bell tower, from Cheops to Strasburg. The past must be reread upon these pages of marble. This book, written by architecture, must be admired and perused incessantly; but the grandeur of the edifice which printing erects in its turn must not be denied.
This [new] edifice [of print] is colossal. Some compiler of statistics has calculated, that if all the volumes which have issued from the press since Gutenberg’s day were to be piled one upon another, they would fill the space between the earth and the moon; but it is not that sort of grandeur of which we wished to speak.
(…)
The press, that giant machine, which incessantly pumps all the intellectual sap of society, belches forth without pause fresh materials for its work. The whole human race is on the scaffoldings [of this new towering edifice]. Each mind is a mason (…) Every day a new course [of this new edifice] rises. (…)  Assuredly, it is a [towering] construction which increases and piles up in endless spirals; there also are confusion of tongues, incessant activity, indefatigable labor, eager competition of all humanity, refuge promised to intelligence, a new Flood against an overflow of barbarians. It is the second tower of Babel of the human race.