The heyday of New Latin was its first two centuries (1500-1700), when in the continuation of the Medieval Latin tradition, it served as the primary language of science, education, and to some degree diplomacy in Europe. Classic works such as Newton's Principia Mathematica (1687) were written in the language. Throughout this period, Latin was a universal school subject, and indeed, the pre-eminent subject for elementary education in Western Europe and those places which shared its culture. All universities required Latin proficiency (obtained in local grammar schools) to obtain admittance as a student.
Through most of the 17th century, Latin was also supreme as an international language of diplomatic correspondence, used in negotiations between nations and the writing of treaties. As an auxiliary language to the local vernaculars, New Latin appeared in a wide variety of documents, ecclesiastical, legal, diplomatic, academic, and scientific. While a text written in English, French, or Spanish at this time might be understood by a significant cross section of the learned, only a Latin text could be certain of finding someone to interpret it anywhere between Lisbon and Helsinki.
Likewise, starting in the 1710s, French replaced Latin as a diplomatic language, due to the commanding presence in Europe of the France of Louis XIV. At the same time, some (like King Frederick William I of Prussia) were dismissing Latin as a useless accomplishment, unfit for a man of practical affairs.
A diminishing audience combined with diminishing production of Latin texts pushed Latin into a death spiral from which it has not recovered. As it was gradually abandoned by various fields, and as less written material appeared in it, there was less of a practical reason for anyone to bother to learn Latin; as fewer people knew Latin, there was less reason for material to be written in the language. Latin came to be viewed as esoteric, irrelevant, and worst of all, too difficult. As languages like French, German, and English came to be more widely known, recourse to a 'difficult' auxiliary language would seem unnecessary; while the argument that Latin could be used to expand readership beyond a single nation was fatally weakened if, in fact, Latin readers did not compose a majority of the intended audience.
As the 18th century progressed, the extensive literature in Latin being produced at the beginning slowly contracted, until by 1800 it was only a trickle. It lasted longest in very specific fields (e.g. botany) where it had acquired a technical character, and where a literature available only to a small number of learned individuals could remain viable. The perpetuation of Ecclesiastical Latin in the Roman Catholic Church through the 20th century can be considered a special case of the same.
By 1900, New Latin was confined to a few very technical areas (e.g., botany) where it often functioned as a code capable of limited types of expression. In other fields (e.g. anatomy or law) where Latin had been widely used, it survived in technical phrases and terminology. The last survivals of New Latin to convey non-technical information appear in the use of Latin to cloak passages and expressions deemed too indecent (in the 19th century) to be read by children, the lower classes, or (most) women — intending to shrink readership, not expand it. Such passages appear in translations of foreign texts and in works on folklore, anthropology, and psychology, e.g. Krafft-Ebing's Psychopathia Sexualis (1886).
Creative Latin composition, for purely artistic purposes, was very rare by the end of the 19th century. Authors such as Arthur Rimbaud and Max Beerbohm wrote Latin verse, but these texts were either school exercises or occasional pieces.
In secular academic use, however, New Latin declined sharply and then continuously after about 1700 A.D. Although Latin texts continued to be written throughout the 18th and into the 19th century, their number and their scope diminished over time. By 1900, very few new texts were being created in Latin for practical purposes, and the production of Latin texts had become little more than a hobby for Latin enthusiasts.
Around the beginning of the 19th century came a renewed emphasis on the study of Classical Latin as the spoken language of the Romans of the 1st centuries BC and AD. This new emphasis, similar to that of the Humanists but based on broader linguistic, historical, and critical studies of Latin literature, led to the exclusion of Neo-Latin literature from academic studies in schools and universities (except for advanced historical language studies); to the abandonment of New Latin neologisms; and to an increasing interest in the reconstructed Classical pronunciation, which was to displace the several regional pronunciations in Europe in the early 20th century.
Coincident with these changes in Latin instruction, and to some degree motivating them, came a concern about lack of Latin proficiency among students. Latin had already lost its privileged role as the core subject of elementary instruction; and as education spread to the middle and lower classes, it tended to be dropped altogether. By the mid-20th century, even the trivial acquaintance with Latin typical of the 19th-century student was a thing of the past.
Ecclesiastical Latin, the form of New Latin used in the Roman Catholic Church, remained in use throughout the period and after. Until the Second Vatican Council of 1962-65 all priests were expected to have competency in it, and it was studied in Catholic schools. It is still today the official language of the Church and the Vatican State. Use of the Latin Mass, restricted through the later 20th century, has recently been broadened by Pope Benedict XVI.
New Latin is also the source of the biological system of binomial nomenclature and classification of living organisms devised by Carolus Linnæus; the need to create names within a superficially Latin structure continues to drive the development of new Latin or quasi-Latin vocabulary today. Another continuation is the use of Latin names for the surface features of planets and planetary satellites (planetary nomenclature), originated in the mid-17th century for selenographic toponyms. New Latin has also contributed a vocabulary, to some extent naturalized in European languages, for specialized fields such as anatomy and law.
The following table illustrates some of the variation of New Latin consonants found in various countries of Western Europe, compared to the Classical Latin pronunciation of the 1st centuries BCE-CE. In Eastern Europe, the pronunciation of Latin was generally similar to that used in Germany.
before æ, e, i, œ, y
before æ, e, i, œ, y
before a, o, u
before æ, e, i
before æ, e, i, œ, y
The letter j generally represented a consonantal sound (pronounced in various ways in different European countries, e.g. [j], [dʒ], [ʒ], [x]). It appeared, for instance, in jam "now" or jubet "orders" (now spelled iam and iubet). It was also found between vowels in the words ejus, hujus, cujus (now normally spelled eius, huius, cuius), and pronounced as a consonant. J was also used when the last in a sequence of two or more i's, e.g. radij (now spelled radii) "rays", alijs "to others", iij, the Roman numeral 3; however, ij was for the most part replaced by ii by 1700.
In common with texts in other languages using the Roman alphabet, Latin texts down to c. 1800 used ſ (the long s), italic ʃ for s in positions other than at the end of a word; e.g. ipʃiʃʃimus.
The diphthongs ae and oe were rarely if ever so written; instead the digraphs æ and œ were used, e.g. Cæsar, pœna. More rarely (and usually in early 17th-century texts) the e caudata is found substituting for either.
The acute accent marked a stressed syllable, but was usually confined to those where the stress was not in its normal position, as determined by vowel length and syllabic weight. In practice, it was typically found on the vowel in the syllable immediately preceding a final clitic, particularly que "and", ve "or" and ne, a question marker; e.g. idémque "and the same (thing)". By some printers, however, this acute accent was placed over the q in que when that clitic followed, e.g. eorumq́ue "and their". The acute accent fell out of favor by the 19th century.
The grave accent had various uses, none related to pronunciation or stress. It was always found on the preposition à (variant of ab "by" or "from") and likewise on the preposition è (variant of ex "from" or "out of"). Most frequently, it was found on the last (or only) syllable of various adverbs and conjunctions, particularly those which might be confused with prepositions or with inflected forms of nouns, verbs, or adjectives. Examples include certè "certainly", verò "but", primùm "at first", pòst "afterwards", cùm "when", adeò "so far, so much", unà "together", quàm "than". In some texts the grave was found over the clitics que et al., in which case the acute accent did not appear before them.
The circumflex accent represented metrical length (generally not distinctively pronounced in the New Latin period) and was chiefly found over an a, when that represented an ablative singular case, e.g. eâdem formâ "with the same shape". It might also be used to distinguish two words otherwise spelled identically, but distinct in vowel length; e.g. hîc "here" differentiated from hic "this", fugêre "they have fled" (=fūgērunt) distinguished from fugere "to flee", or senatûs "of the senate" distinct from senatus "the senate". It might also be used for vowels arising from contraction, e.g. nôsti for novisti "you know", imperâsse for imperavisse "to have commanded", or dî for dei or dii.