Before the microscope revealed to us the hidden world of bacteria, scientists never dreamt that creatures existed that were invisible to the naked eye.
The size of average bacteria is about two microns by half a micron (a micron being a millionth of a meter, or a millionth of 39.37 inches). This means that laid end to end, there are 500,000 bacteria in a meter (or in 39.37 inches), or 2,000,000 laid side by side.
The first step towards discovering the existence of bacteria was taken by the Dutch scientist, Antony van Leeuwenhoek (1632-1723), using an early form of microscope which he helped develop. This was a simple brass plate fitted with a single polished lens, able to magnify 200 times. Despite its relatively weak power, it allowed Leeuwenhoek to discern tiny creatures moving within materials taken from between people’s teeth. However, it was only in the second half of the 19th century that the existence of bacteria and their role as vectors of disease was finally verified.
The famous French scientist, Louis Pasteur (1822 – 1895), was the most important 19th century researcher into micro-organisms and their relationship to various diseases. After discovering the existence of bacteria, Pasteur introduced disinfectant methods into hospitals and clinics, which rid them of these invisible menaces. Prior to Pasteur’s work, a single, dirty scalpel might have been used to perform multiple surgeries. This unwitting transfer of bacteria from one person to another resulted in extremely high death rate among patients. No one had previously drawn a connection between the bacteria-laden instruments and patient deaths. After Pasteur introduced his disinfectant methods, patient death rates dropped sharply.
Continuing his research, Pasteur found that heat could destroy harmful bacterial present in cow’s milk. As a result of this discovery, millions of infants previously unable to breastfeed were saved from death. The process he developed was subsequently named after him – pasteurization.
It turns out that less than 150 years have passed since scientists discovered the following:
A. The existence of bacteria.
B. The fact that bacteria cause and transmit disease through the blood or other bodily secretions of an infected patient.
C. The fact that bacteria can be destroyed by heat. (Another recent discovery has shown that high body temperature brought on by infections itself serves to destroy bacteria within the body).
One of the more recent discoveries in the field of micro-biology is the possibility for a person to carry a dangerous strain of bacteria without being harmed, yet cause harm to others when transmitting the bacteria to them.
Once again, to our amazement, in the Code of Jewish Law, in the section dealing with proper table manners, we find the following admonition:(1)
“A man shall not drink from a cup then give it to another, because of life-threatening dangers.”
This idea is explained in the teachings of Rabbi Eliezer the Great:(2)
“For perhaps there is an illness in his body, which might go from his mouth into the cup, making his friend ill.”
In other words, Rabbi Eliezer, who lived some 2,000 years ago, already knew that:
A. Illness can be attributed to invisible factors, which are present not only within the affected organ, but throughout the sick person’s body, including his bodily secretions.
B. These invisible transmitters can pass from person to person by indirect means, such as sharing the same cup, thereby infecting the second person.
C. Most important is that even a healthy person must not share his cup with others, lest “there is an illness in his body.” In other words, even an apparently healthy person may carry a strain of bacteria that is harmless to him, but might cause illness in another.
Beyond the reasons given by Rabbi Eliezer the Great, we should note the additional reason of Rabbi Shlomo Luria:(3) “For his fellow might be disgusted by drinking from the same cup, but do so out of embarrassment, against his will, and suffer thereby.”
There is further evidence that the Sages knew of the existence of microbes and bacteria, based upon the following statement of the Talmud,(4) written some 1600 years ago:
“Samuel Said: An open wound caused by a piece of iron is to be regarded as life threatening, and one is allowed to profane the Sabbath [in order to treat it].”
In general, Sabbath desecration is permissible only to treat life-threatening illnesses; thus, treating a simple wound is forbidden. However, when a wound was caused by a piece of iron, it should be treated even with procedures that involve Sabbath desecration, for the Sages realized that even a superficial wound of this type can be life threatening.
Did medical experts of the time find this statement puzzling, seeing that it refers to a relatively minor wound? And why should such a wound be considered life threatening?
Today, we know that rusty iron contains bacteria that can cause a Tetanus infection, also known as Lockjaw, and that the entry of these bacteria into the body through even a superficial wound can ultimately be lethal.
The Torah Sages knew this before the advent of modern science. Scientific opinion at the time (and till centuries later) denied any connection between superficial wounds and life threatening illness. Indeed, before the discovery of bacteria, there was no good reason to imagine that a small wound could cause death. Non-Jewish medical experts would have claimed that the patient died from some previous, internal disease. And undoubtedly, they would not have recommended that a Jew profane the Sabbath in such circumstances. Yet, despite the Sages' efforts to preserve the sanctity of the Sabbath, they were not ready to accept the current medical opinion in this case. Their knowledge had been passed on from generation to generation, and they knew that a wound caused by iron could be life threatening. Appropriately, they gave practical instructions to treat such a wound, even being small, for in this case, size is irrelevant and such wounds can cause a massive, lethal infection. As we know today, scientists eventually reached the same conclusion through their research.
The Discovery of Pasteurization information presented in the Sages’ comments quoted above.
Based upon a story in the Talmud, we can see that the Torah Sages of the time also understood the importance of strict cleanliness during surgical procedures.
The Talmud(9) describes an operation performed on Rabbi Elazar, the son of Rabbi Shimon ben Yochai: “He was given a sleeping draught, taken into a marble chamber and had his abdomen opened…”
Note that the surgery was performed in a marble-lined room, which is easier to clean and keep dust-free. Undoubtedly, a special chamber had been designed to maintain the highest level of cleanliness, to provide the proper environment for the surgery, and to prevent the patient’s body from becoming infected.
Notes and Sources
(1) Masechet Derech Eretz, chap. 7.
(2) Quoted in Turei Zahav, a basic commentary on the Shulchan Aruch by Rabbi Dovid ben Shmuel HaLevi (1586-1667), one of the foremost rabbinical authorities in seventeenth-century Poland. Section 170, paragraph 8.
(3) In his commmentary on the Tur, Orach Chayim 170.
(4) BT Avodah Zara 28a.
(5) BT Baba Metziah29b.
(6) We must remember that at the time, water was drawn primarily from wells and cisterns and did not undergo the standard purification processes of today.
(7) It is important to realize that water boiled in glass vessels still contains the dissolved salts and rust that were there previously. When boiled in metal vessels, however, salts and rust precipitate out and are deposited onto the vessels bottom and walls. Thus, in metal vessels, the water is cleaner.
(8) Part 3, chap. 14.
(9) BT Baba Metzia 83b.