Mishnah Mikvaos 7:1: There are those that raise [i.e. that count towards the measure of it waters to reach forty se'ah, to complete] a mikveh [a gathering of water collected by natural means and immersed in for purification] and do not invalidate it, [those that] invalidate but do not raise, [and those that] do not invalidate and do not raise. These raise and do not invalidate: snow, and hail, and frost, and ice, and salt, and mud that can be poured. Rabbi Akiva says: Rabbi Yishmael would rule against me, saying, "Snow does not raise a mikveh." But the people of Midva testified in his name that he said to them, "Go out and bring snow to make a mikveh from the outset." Rabbi Yochanan ben Nuri says: A hailstone is like water. How do these raise and not invalidate? If there is a mikveh containing forty se'ah [a specific unit of volume] less one, and a se'ah [of one] of these fell into it, and raised it [to be a complete mikveh containing forty se'ah], we find thus that these raise and do not invalidate.

יֵשׁ מַעֲלִין אֶת הַמִּקְוֶה וְלֹא פוֹסְלִין, פּוֹסְלִין וְלֹא מַעֲלִין, לֹא מַעֲלִין וְלֹא פוֹסְלִין. אֵלּוּ מַעֲלִין וְלֹא פוֹסְלִין, הַשֶּׁלֶג, וְהַבָּרָד, וְהַכְּפוֹר, וְהַגְּלִיד, וְהַמֶּלַח, וְהַטִּיט הַנָּרוֹק. אָמַר רַבִּי עֲקִיבָא, הָיָה רַבִּי יִשְׁמָעֵאל דָּן כְּנֶגְדִּי לוֹמַר, הַשֶּׁלֶג אֵינוֹ מַעֲלֶה אֶת הַמִּקְוֶה. וְהֵעִידוּ אַנְשֵׁי מֵידְבָא מִשְּׁמוֹ שֶׁאָמַר לָהֶם, צְאוּ וְהָבִיאוּ שֶׁלֶג וַעֲשׂוּ מִקְוֶה בַּתְּחִלָּה. רַבִּי יוֹחָנָן בֶּן נוּרִי אוֹמֵר, אֶבֶן הַבָּרָד, כַּמָּיִם. כֵּיצַד מַעֲלִין וְלֹא פוֹסְלִין. מִקְוֶה שֶׁיֶּשׁ בּוֹ אַרְבָּעִים סְאָה חָסֵר אַחַת, נָפַל מֵהֶם סְאָה לְתוֹכוֹ וְהֶעֱלָהוּ, נִמְצְאוּ מַעֲלִין וְלֹא פוֹסְלִין:

Mishnah Mikvaos 7:2: These invalidate and do not raise: [drawn] waters, whether pure or impure, and picking waters, and waters in which foods were boiled, and inferior wine [made by fermenting grape residue steeped in water] that has not yet fermented. How do they invalidate and not raise? If there is a mikveh containing forty se'ah less one kortov [A minute volume measure], and one kortov [of one] of these fell into it, it has not raised it [to be a full forty se'ah and thus a complete mikveh]; and three log of it [of any of these] would invalidate [such a mikveh]. But the remaining liquids [such as oils and wines], and fruit juices, and juices of salted fish, and fish brine, and inferior wine once it has fermented, [all of these] at times raise [a mikveh to be complete] and at times do not raise. How so? If there is a mikveh containing forty se'ah less one, and a se'ah [of one] of these fell into it, it has not raised it [to be complete]. If it contained forty se'ah [at the outset], and one added a se'ah [of one of these] and [then] took out a se'ah, it is thereby valid.

אֵלּוּ פוֹסְלִין וְלֹא מַעֲלִין, הַמַּיִם, בֵּין טְמֵאִים בֵּין טְהוֹרִים, וּמֵי כְבָשִׁים וּמֵי שְׁלָקוֹת, וְהַתֶּמֶד עַד שֶׁלֹּא הֶחֱמִיץ. כֵּיצַד פּוֹסְלִין וְלֹא מַעֲלִין. מִקְוֶה שֶׁיֶּשׁ בּוֹ אַרְבָּעִים סְאָה חָסֵר קֹרְטוֹב, וְנָפַל מֵהֶן קֹרְטוֹב לְתוֹכוֹ, לֹא הֶעֱלָהוּ, פּוֹסְלוֹ בִשְׁלשָׁה לֻגִּין. אֲבָל שְׁאָר הַמַּשְׁקִין, וּמֵי פֵרוֹת, וְהַצִּיר, וְהַמֻּרְיָס, וְהַתֶּמֶד מִשֶּׁהֶחֱמִיץ, פְּעָמִים מַעֲלִין וּפְעָמִים שֶׁאֵינָן מַעֲלִין. כֵּיצַד. מִקְוֶה שֶׁיֶּשׁ בּוֹ אַרְבָּעִים סְאָה חָסֵר אַחַת, נָפַל לְתוֹכוֹ סְאָה מֵהֶם, לֹא הֶעֱלָהוּ. הָיוּ בוֹ אַרְבָּעִים סְאָה, נָתַן סְאָה וְנָטַל סְאָה, הֲרֵי זֶה כָשֵׁר: