On his return to Madras, he drew up for the governor-general (Lord Elphinstone) a report on the Khonds, and the measures to be adopted for the suppression among that people of the Meriah, or human sacrifices.

In the meantime, Captain (afterwards General) Campbell, assistant to the collector of Ganjam, had called together the chief men of the Khonds of Gumsur, and informed them that human sacrifices would no longer be tolerated by the company's government, and had compelled them to give up a number of intended victims.

He administered justice among them with unflagging industry; he strove to conciliate the curate, priests, and rajahs; he vigorously punished the Hindus who carried on the nefarious traffic of supplying victims to the Khonds ; he constructed roads, encouraged fairs, and bestowed the Meriah girls in marriage on the most influential persons among the tribes, and made these alliances a passport to the favour of fovernment.

He obtained the support of Macpherson's superiors, and when in November 1845, Macpherson having been appointed 'governor-general's agent for the suppression of Meriah sacrifice and female infanticide in the hill tracts of Orissa,' proceeded to extend his measures to Boad, a district north of Gumsur, the Hindu's sons raised a rebellion and attacked the camp of the agent.

He was appointed in succession as agent at Benares and at Bhopal, but in July 1854, being then brevet-major, he was transferred to the more important post of Gwalior, the capital of Sindhia, the most powerful native ruler in Central India.

Sindhia's minister, Dinkar Rao, was a statesman of the first order; and Macpherson took care that his administrative genius should have free play.

He abolished the transit duties; laid out large sums on the roads and public works; drew up a capital code of law and civil procedure, and raised the revenue from a deficit to a surplus.

When the Sipahi mutinies broke out in 1857, it was Dinkar, influenced by Macpherson, who kept the Gwalior contingent and Sindhia's own army from joining the rebels in Delhi.