In the case of Gas Company v. Pittsburgh, the Supreme Court of the United States was asked to decide whether a gas company had the right to construct a gas works in the city of Pittsburgh. The gas company had been granted a charter by the state of Pennsylvania to construct the works, but the city of Pittsburgh had passed an ordinance prohibiting the construction. The gas company argued that the ordinance was unconstitutional because it violated the company's rights under the charter. The Supreme Court held that the ordinance was unconstitutional because it violated the company's rights under the charter. The Court reasoned that the charter was a contract between the state and the company, and that the ordinance interfered with the company's rights under the contract. The Court also held that the ordinance was an unconstitutional exercise of the city's police power, as it was not necessary to protect the public health, safety, or welfare. The Court concluded that the ordinance was unconstitutional and that the gas company had the right to construct the gas works in the city of Pittsburgh. The Court's decision established that the rights of a company under a charter granted by the state could not be infringed upon by a local ordinance.

Justice Field delivered the dissenting opinion in this case. He argued that the city of Pittsburgh had no right to impose a tax on gas companies, as it was not authorized by any law or charter from Pennsylvania's legislature. The majority opinion held that such taxes were permissible under state laws and could be imposed without legislative approval. Justice Field disagreed with this interpretation, arguing that if cities are allowed to levy taxes without legislative authority then they would have too much power over businesses operating within their jurisdiction. Furthermore, he noted that allowing local governments to impose taxes would lead to an unequal taxation system across different states and municipalities since each locality can set its own rates for taxation purposes. In conclusion, Justice Field believed that only the legislature should have the power to create new forms of taxation and thus concluded his dissent against allowing Pittsburgh’s tax on gas companies stand as valid law.