The Beraisa lists five attributes of a mad dog.

Question: How did it become this way?

Answer (Rav): Witches fun.

Answer (Shmuel): Evil spirits.

Question: What difference does it make how it became mad?

Answer: Whether to kill it only from a distance (Shmuel, lest the evil spirits attack the person) or even from close (Rav).

A Beraisa supports Shmuel, indicating also that it is dangerous to rub against a mad dog (and lethal to be bitten by one).

The Gemara describes the procedure (removing one's coat, etc) for dealing with the dangers created by rubbing against such a dog (and R. Huna was able to save himself with this knowledge).

The Gemara describes the incantation and procedure needed to save one who was bitten by such a dog.

During the 12 months of the procedure the victim should not drink from a cup in a manner which would allow the image of the offending spirit to endanger the victim who would see it.

This precaution was taken in the case of Aba b. Marta.

When a gentile matron administered a cure for R. Yochanan's Tzafidna for two consecutive days - he asked her for instructions on how to prepare it himself, should the need arise on Shabbos.

She made him swear by the G-d of Israel that he would not divulge the formula; he swore and then divulged the secret.

He did not break his promise - because when she demanded that he swear by the G-d of Israel that he would not so, he inverted her words, and swore that he would not divulge her secret to the G-d of Israel.

Neither did he create a Chilul Hash-m by causing her to think that he was breaking his promise - because he informed her immediately as to what he had done.

Some say that the secret cure was yeast-water, olive oil and salt.

There are two other opinions:

The first, replaces yeast-water with ... yeast.

The second states only one ingredient - the oil from one of the feathers on a goose's wing.

(Abaye): None of the above methods work, however, an Arab told him to use date-stones that had not yet grown a third - which he was to burn in the fire produced by burning a new hoe, and to place the ashes on his teeth.

Question: How does one contract Tzafidna?

Answer: Tzafidna is caused by eating very hot bread and the remnants of fish fried in flour, in their own oil.

Question: How does one know that he has contracted it?

Answer: When his teeth bleed easily.

R. Yochanan permitted this cure (for Tzafidna) on Shabbos.

Question: In accordance with whom is this Heter?

Answer: R. Masya b. Charash (who maintains in our Mishnah that any illness inside the mouth is considered life- threatening).

Question (R. Chiya b. Aba): But the Chachamim disagree (in the case of the Chatzar Kaved)!?

Answer (R. Yochanan): The Chachamim argued only regarding that particular procedure, not regarding other medications.

A Beraisa seems to support R. Yochanan's contention:

(R. Masya b. Charash): A person...

with jaundice is permitted to eat donkey's meat.

bitten by a mad dog may eat part of its liver.

whose mouth hurts may take medicine.

(Chachamim): 'be'Eilu Ein Bahem Mishum Refu'ah'.

Question: What are the Chachamim specifying (and excluding) with 'be'Eilu'?

Answer: The jaundice and mad dog bite are not a Refu'ah and the throat medicine is (like R. Yochanan).

No, the Chachamim are arguing with all three Refu'os, and only concede the efficacy of a fourth case, letting blood for someone who has Serunchi.

This seems to be supported by the Beraisa.

The Chachamim (referring to three lenient rulings of R. Masya b. Charash, the first of which is letting blood for Serunchi) comment 'be'Eilu Ein Bahem Mishum Refu'ah'.

Presumably 'be'Eilu' challenges the effectiveness of the last two stated cases, and excludes the first (allowing that it is effective).

No, R. Yochanan may be defended, as 'be'Eilu' can refer to the first two cases, and the Chachamim are allowing for the effectiveness of the last case (medicine for oral pain).

R. Yochanan may be supported from a third Beraisa.

(R. Elazar b. R. Yosi citing R. Masya b. Charash): It is permitted to feed:

a pregnant woman until she recovers;

Chatzar Kaved for a mad dog bite; and,

medicine on Shabbos for oral pain.

(Chachamim): 'be'Zu ve'Lo ba'Acheres'.

Question: To which case do the Chachamim refer?

Answer: To the pregnant woman.

Question: Their agreement to this case is obvious!

Answer: They must refer to, and agree with, the medicine for oral pain (they cannot refer to the Chatzar Kaved since the Chachamim explicitly argue in the Mishnah on this case).

This, indeed, supports R. Yochanan, and R. Ashi infers this from the (manner in which the cases are listed that the Chachamim are arguing in the) Mishnah itself.

Question: Why does the Mishnah tell us, again (after teaching that someone with mouth pains is a case of Safek Nefashos), that all Safek Nefashos is Docheh Shabbos?

Answer (R. Yehudah citing Rav): To permit breaking the Shabbos even if he might die on a different Shabbos (but would certainly survive this one).

Question: What would be an example?

Answer: The doctors assessed that the patient needed to take cures for eight days and we might otherwise have thought that we may as well wait for night-fall and begin taking the medicine only after Shabbos, in order to avoid unnecessary Chilul Shabbos.

This is borne out by a Beraisa, which permits breaking this Shabbos for a Safek Piku'ach Nefesh next Shabbos.

Where it is necessary to save a Jew's life, we do not rely on a gentile or a child to do so (in the most effective manner) but rather an adult Jew should do the Chilul Shabbos.

We are not Mechalel Shabbos based only on the assessment of women or gentiles, however, they combine with another person to permit the patient to eat (even against two others saying that he need not).

The Beraisa teaches in four cases that one who is quick to be Mechalel Shabbos and save a life is praiseworthy, and then teaches that he need not obtain permission from Beis Din.

The Gemara explains by each case why one who is praiseworthy might think to nevertheless seek permission.

By a child who fell into the sea (even though the person who saves will also catch fish for himself).

By a child who fell into a deep pit (even though he fashions a ladder for himself).

By a child on whom the door closed and locked (even though he seeks to use the splinters from the door).

By someone who was trapped by an oncoming fire (even though he intends to preserve the coals thereby).

We need to be taught each of the four cases, owing to the peculiarities of each case.

The child who fell in the sea would be swept away if time were allowed for questions, unlike the child in the pit.

The child in the pit may go into shock whereas we might be able to play games with the child on the other side of the door until after Shabbos.

And we repeat the Heter regarding an oncoming fire even if the child is in another court-yard.

(R. Yosef citing R. Yehudah citing Shmuel): In matters of life and death, we do not follow the majority.

Question: Under what circumstances are we taught this Din?

Answer 1: In the case of a wall which fell onto a group of nine Jews and one gentile, burying one beneath it, and we do not know which one.

Question: But there it is obvious that we will follow the majority in order to save a life!?

Answer 2: It speaks of the case where the group consists of five Jews and five gentiles.

Question: But that is a regular case of Safek Nefashos Lehakel!?

Answer 3: It speaks where there are nine gentiles and one Jew.

Question: But the principle of 'Kol Kavu'a' makes that case obvious, as well (it is no different than 50-50)!?

Answer 4: It speaks of the case in Answer 3, however, where the wall fell on him after they had moved to another court-yard.

We should apply the principle 'Kol de'Parish, me'Rubah Parish' (making it forbidden to save him on Shabbos).

Shmuel has thus taught that we do not follow the Rov in matters of Piku'ach Nefesh.

Question: But R. Yochanan has taught that in just such a case of nine Gentiles and one Jew, we only save the one person in that Chatzer, not in another Chatzer!?

Answer: Shmuel speaks where they all moved to the other Chatzer, thus we have established that a Jew is among the group in the new Chatzer, while R. Yochanan forbids where only some of the group moved to the new Chatzer.