Charak Samhita
रसरक्ताश्रितः साध्यो मेदोमांसगतश्च यः। अस्थिमज्जगतः कृच्छ्रः शुक्रस्थो नैव सिद्ध्यति ॥८३॥
The jwara in which doshas are located in the rasa, rakta, mamsa and meda dhatu are curable, while those in which the location is in the asthi and majja dhatu are difficult to treat. The jwara in which the vitiated dosha are located in shukra dhatu is incurable.
english translation
rasaraktAzritaH sAdhyo medomAMsagatazca yaH। asthimajjagataH kRcchraH zukrastho naiva siddhyati ॥83॥
hk transliteration by Sanscript