renewed in 1768: Carey and Bioren, _Laws_, I. 451; _Penn. Col.
Rec._, IX. 472, 637, 641.

[36] _Penn. Col. Rec._, VIII. 576.

[37] A large petition called for this bill. Much altercation
ensued with the governor: Dallas, _Laws_, I. 671, ch. 692;
_Penn. Col. Rec._, X. 77; Bettle, in _Penn. Hist. Soc. Mem._,
I. 388-9.

[38] Dallas, _Laws_, I. 782, ch. 810.

[39] _Ibid._, I. 838, ch. 881.

[40] There exist but few estimates of the number of slaves in
this colony:--

In 1721, 2,500-5,000. _Doc. rel. Col. Hist. New York_, V. 604.
" 1754, 11,000. Bancroft, _Hist. of United States_ (1883),
II. 391.
" 1760, very few." Burnaby, _Travels through N. Amer._ (2d ed.),
p. 81.
" 1775, 2,000. _Penn. Archives_, IV 597.

[41] Dallas, _Laws_, II. 586.

[42] Cf. _Argonautica Gustaviana_, pp. 21-3; _Del. Hist. Soc.
Papers_, III. 10; _Hazard's Register_, IV. 221, §§ 23, 24;
_Hazard's Annals_, p. 372; Armstrong, _Record of Upland
Court_, pp. 29-30, and notes.