Mishnah Taharos 5:7: One who sat in the public domain, and someone came and stepped on his clothes, or spat and he [the sitter] touched his spit: on account of the spit the terumah is burned, but regarding the [stepped on] clothes we follow the majority [of the area's population, in order to determine the status of the person who stepped on the clothes, and thereby to determine whether or not the sitter was rendered impure]. One who slept in the public domain, when he arises his clothes are impure as midras [an impurity caused when something is sat or stepped upon by a zav or a zava, rendering it an Origin of impurity], according to Rabbi Meir; but the Sages declare them pure. One who touched someone in the night, and it is not known whether it was someone living or dead, and in the morning when he arose he found him dead, Rabbi Meir declares him pure; but the Sages declare him impure, since all [uncertain cases of] impurities are [ruled] in accordance with [their apparent status at] the time they are discovered.

מִי שֶׁיָּשַׁב בִּרְשׁוּת הָרַבִּים וּבָא אֶחָד וְדָרַס עַל בְּגָדָיו, אוֹ שֶׁרָקַק וְנָגַע בְּרֻקּוֹ, עַל רֻקּוֹ שׂוֹרְפִים אֶת הַתְּרוּמָה, וְעַל בְּגָדָיו הוֹלְכִין אַחַר הָרֹב. יָשֵׁן בִּרְשׁוּת הָרַבִּים וְעָמַד, כֵּלָיו טְמֵאִים מִדְרָס, דִּבְרֵי רַבִּי מֵאִיר. וַחֲכָמִים מְטַהֲרִין. נָגַע בְּאֶחָד בַּלַּיְלָה, וְאֵין יָדוּעַ אִם חַי אִם מֵת, וּבַשַּׁחַר עָמַד וּמְצָאוֹ מֵת, רַבִּי מֵאִיר מְטַהֵר. וַחֲכָמִים מְטַמְּאִים, שֶׁכָּל הַטֻּמְאוֹת כִּשְׁעַת מְצִיאָתָן:

Mishnah Taharos 5:8: If there was even one shotah in the town, or a non-Jewish woman, or a Samaritan woman, all spit [found] in the town is impure. Someone whose clothes were stepped on by a woman, or if she sat with him in a boat, if she knows that he is one who eats terumah [and therefore has to be careful to remain pure, then] his clothes are pure; but if not, he must ask her [if she is a niddah, in order to determine whether or not his clothes have become impure].

שׁוֹטָה אַחַת בָּעִיר, אוֹ נָכְרִית, אוֹ כוּתִית, כָּל הָרֻקִּים שֶׁבָּעִיר טְמֵאִין. מִי שֶׁדָּרְסָה אִשָּׁה עַל בְּגָדָיו, אוֹ שֶׁיָּשְׁבָה עִמּוֹ בִּסְפִינָה, אִם מַכִּירָתוֹ שֶׁהוּא אוֹכֵל בַּתְּרוּמָה, כֵּלָיו טְהוֹרִין. וְאִם לָאו, יִשְׁאָלֶנָּה: