Linguist Albrecht Wirth 1914 - Macedonians are a own branch
The work "Der Balkan. Seine Länder und Völker in Geschichte, Kultur, Politik, Volkswirtschaft, und Weltverkehr" (The Balkans. Its Countries and Peoples in History, Culture, Politics, Economics and World Transport) by german linguist Albrecht Wirth dates from 1914. Published in Stuttgart (Germany) in the first year of the First World War in 1914, this work was more or less a universal encyclopedia in written format. With important informations about the history of the Balkans and its inhabitants.
On page 214, Wirth describes the South Slavs, and there we read:
Ursprünglich gibt es zwei große Zweige der Südslawen: Serben und Slowenen; dann könnten allenfalls die Mazedonier als eigener Stamm gelten. Durch Mischung der Slowenen mit einem awarischen Volk entstanden die Bulgaren.
[English]
Originally there are two big branches of the south Slavic people, Serbians and Slovenians, then at most the Macedonians could be seen as a own branch. Through a mix between the Slovenians and an Avaric tribe, the Bulgarians were created.
Thus there is a clear differentiation between the Macedonians as an independent people to the Serbs and Bulgarians.
Shortly afterwards, Wirth explains how many Bulgarians lived in what was then the Kingdom of Bulgaria. So we read:
Die Bulgaren können im Königreich mit 3,2 Millionen angenommen werden, zusammen mit den Mazedoniern 4 Millionen.
[English]
The Bulgarians in the Kingdom are about 3.2 million people, together with the Macedonians 4 million people.
From these lines it can be seen that, according to Wirth, around 800,000 Macedonians lived in the Kingdom of Bulgaria, which Wirth clearly differentiates from the Bulgarians.
In the section on the southern Slavs, Wirth also devotes himself to the Greeks. He represents the theses of Jakob Philipp Fallmerayer, who saw the modern Greeks more as Slavs. So we read:
In einem hat Fallmerayer, der seine Gegner an Geist weit überragte, vollkommen recht: dass schon im achten Jahrhundert, ganz Griechenland bis zum Kap Matapan von Slawen bewohnt war und dass selbst Sparta und die Hänge des Tajgetos Hauptsitze slawischer Stämme wurden. Auch das wird man von ihm annehmen, dass es noch zu seiner Zeit, also um das Jahr 1840, so manche Gegenden gab, namentlich Attika selber, in denen Albanisch besser als Griechisch verstanden wurde.
[English]
Fallmerayer, who far surpassed his opponents in spirit, is absolutely right about one thing: that as early as the eighth century, all of Greece up to Cape Matapan was inhabited by Slavs and that even Sparta and the slopes of the Tajgetos became the headquarters of Slavic tribes. One will also assume that in his time, around 1840, there were some areas, namely Attica itself, where Albanian was understood better than Greek.
Source: "Der Balkan. Seine Länder und Völker in Geschichte, Kultur, Politik, Volkswirtschaft, und Weltverkehr”, Albrecht Wirth, Stuttgart 1914.
Note: Title picture not connected to the quoted source