JN-25B was introduced on 1 December 1940, but was broken immediately by FECB as the additives were not changed.
dʒˌeɪˈɛn twˈɛnti fˈaɪv bˈiː wʌz ˌɪntɹədˈuːst ˌɔn wˈʌn dᵻsˈɛmbɚ nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi, bˌʌt wʌz bɹˈoʊkən ɪmˈiːdɪətli baɪ fˈɛkb æz ðɪ ˈædᵻtˌɪvz wɜː nˌɑːt tʃˈeɪndʒd.