From a linguistic point of view, this manuscript is presented as a list of words in African languages, translated into Portuguese, organized by semantic fields. It also provides some dialogues and phrases needed for the most urgent communication.  
Castro published an ethno-linguistic critical essay on the Peixoto manuscript, considering it to be multifunctional in character, 'bringing together real elements of the history and sociology of Brazilian blacks in colonial times' (2002, p. 25). The author identifies the language as Mina-Jeje, with Fon as its fundamental lexical base. Bonvini (2008, p. 45) classifies the Mina language as a vehicular tongue based on Gbe (designation of a set of languages spoken in Togo and Benin) in a pidginization phase. What we can say with certainty is that this document reveals a unique linguistic fact: the presence of an African vehicular language, without any apparent mixing with Portuguese, whether in terms of lexicon, syntax or even phonology (Petter, 2006, p. 128). However, this 'language', or rather its vocabulary, did not remain in the Portuguese spoken in Brazil, not even in the mining region. Nevertheless, according to Castro (2002, p. 27),  
'[...] these tongues [...] ended up laying the foundations of the conventual structure of religious communities of Mina-Jeje tradition in Brazil [...].'