233. It is to be observed, however, that those corporations which serve the public or contribute to the comfort and convenience of the general public, though owned and managed by private interests, are now (and quite appropriately) denominated ‘public-service corporations.” See infra. Another distinction between public and private corporations is that the former are not voluntary associations (as the latter are) and that there igs no contractual relation between the government and a public corporation or between the individuals who compose it. Mor. Priv. Corp.