| RefNo | RB/1/10/25 | 
| Previous numbers | BP 10, fols. 27-8 | 
| Level | Item | 
| Title | Part of introduction to unpublished `Essay XIII' of 'Usefulness'. | 
| Date | 1660s | 
| Description | Continued from BP 28, pp. 293-6.\r\nHand: E, corrections by Boyle? | 
| Language | English | 
| Extent | Fols. 27-8 (2 leaves) | 
| Format | Manuscript | 
| Notes | There is a little flap sticking up with the words 'Mutuall Usefulness' on it. | 
| AccessStatus | Open | 
| RelatedMaterial | Published in  'Works', vol. 13, pp. 350-2.\r\nSee also BP 9, fols. 162-3, BP 24, pp. 375-85, BP 28, pp. 293-5 and BP 29, fols. 207-18. |