In the case of Ballew v. United States, the Supreme Court ruled on whether a five-member jury in a criminal trial was constitutional. The defendant, William Ballew, had been convicted by such a jury for distributing obscene material. He appealed his conviction arguing that it violated his Sixth Amendment right to an impartial jury because federal law required juries to have at least six members. In its decision, the Supreme Court agreed with Ballew and overturned his conviction stating that reducing the size of a jury below six would undermine public confidence in criminal justice system and diminish accuracy of fact-finding process due to less deliberation among jurors leading potentially to more erroneous decisions.

The Ballew v. United States case you're referring to seems to be from 1978, not 1895. In this case, the dissenting opinion was delivered by Justice Rehnquist who disagreed with the majority's decision that a five-person jury in a criminal trial is unconstitutional. He argued that there was no empirical evidence or historical precedent supporting the notion that smaller juries are less effective at fact-finding than larger ones. Furthermore, he pointed out inconsistencies in previous rulings where six-member juries were deemed constitutional but five members were not. He also criticized the majority for overstepping their judicial role and making policy decisions better left to legislatures about what constitutes an ideal jury size.