30 HARVARD LAW REVIEW. statute has removed the reason for the exception, which, therefore, falls, leaving the general rule in force freed from the exception. But such reasoning seems artificial to the last degree in a question of the interpretation of a statute. Heretofore witnesses could not be compelled to give self-incriminatory evidence. It would seem that if the statute had been intended to change the rule, it would have provided in terms that witnesses could be compelled to give such evidence, more especially since the change was in derogation of a well-settled principle of personal right. 1 The statute is sus- ceptible of a perfectly reasonable construction, leaving the privi- lege intact, viz., of extending to witnesses voluntarily giving self-incriminatory evidence the same protection that the common law afforded a witness compelled to give such evidence on com- pulsion against his claim of privilege. Louis M. Greeley. Chicago, III., March 19, 1891. CONSTITUTIONAL CHECKS UPON MUNICIPAL ENTERPRISE'. "A/^ have established, we think, beyond cavil," said Judge VV Miller in Loan Association v. Topeka, 20 Wall. 655, 664 (1874), "that there can be no lawful tax which is not laid for a public purpose." This rule possibly narrows the dis- cussion by shifting it from the question what is a lawful tax, to the question what is a public purpose ; but the difficulty of applica- tion still remains, and is well shown by the case itself which states the rule. That case holds that a law of Kansas authorizing the city of Topeka to encourage by the payment of bounties the establishment of manufactories and " such enterprises as may tend to develop and improve such city," is unconstitutional. Later decisions are to the same effect. 2 On the other hand, the same court has repeatedly held that 1 Hare on Discovery, p. 137, citing Orme v. Crockford, 13 Price, 376, and other cases. 2 Parkersburg v. Brown, 106 U. S. 487 ; Cole v. LaGrange, 113 U. S. I.
