If interrupted vowels are single nuclei, then a strong generalisation may be made regarding the distribution of voiceless and fortis consonants, that is, they are limited to final syllables.
Aqua fortis (nitric acid) was used for separating the metals.
Fricatives include only lenis and fortis distinctions.
The result is that voiceless fricatives are inherently rather than derivatively fortis whereas, parallel to the voiced series of stops, voiced fricatives are lenis and only weakly or coincidentally voiced.
Gimson (1980 : 155) considers voiceless ' fortis ' stops to be ' weakly aspirated ' in these positions.
Fifth, voiceless obstruents and ' fortis ' nasal consonants may occur before interrupted sequences.
They include, for instance, the fortis-lenis (roughly voicelessvoiced) distinction, since the devoicing of lenis consonants was found to cause serious intelligibility problems in lingua franca communication.
What a difference the nature of the fortis-lenis distinction makes.
