Fresh militia and volunteers arrived in camp, whose numbers were exaggerated by report.

These additions to his small remaining regular force enabled the General to take different positions near the lines of the enemy, to harass him perpetually, restrain his foraging parties, and produce considerable distress in his camp.
{January 12.} While, with little more than an imaginary army, General Washington thus harassed and confined his adversary, he came to the hazardous resolution of freeing himself and his troops from the fear of a calamity which he found it impossible to elude, and which had proved more fatal in his camp than the sword of the enemy.
[Sidenote: American army inoculated.] Inoculation having been rarely practised in the western world, the American youth remained liable to the small pox.

Notwithstanding the efforts to guard against this disease, it had found its way into both the northern and middle army, and had impaired the strength of both to an alarming degree.

To avoid the return of the same evil, the General determined to inoculate all the soldiers in the American service.

With the utmost secrecy, preparations were made to give the infection in camp; and the hospital physicians in Philadelphia were ordered to carry all the southern troops, as they should arrive, through the disease.