In Search of the Niinja (26 page)

•
    dinitrogen pentoxide and nitric dioxide (N
2
O
5
)

The following chemicals are produced on combustion of the sulphur that is present in the blood:

•
    sulphur trioxide (SO
3
)

•
    sulphur dioxide (SO
2
)

The latter chemical, sulphur dioxide
,
alongside carbon monoxide, are the strongest contenders for effectiveness. Sulphur dioxide is a strong irritant to the respiratory tract and prolonged exposure to even small concentrations, measurements in the order of parts per billion (ppb), can cause sore throats, fatigue and disorders of sensory apparatus, including irritation to the eyes and nose.

The size of the paper required to succeed in creating a sleeping gas is not given, therefore the following example is based on a ten-centimetre-square of paper to gain a standard model. It is unknown if all the blood contained in the paper will produce a sulphur derivative or not (however a selection of percentages is given further on).

A square of paper, 10cm
2
weighs approximately 2.4g and it can be assumed that after absorbing the blood, the total weight will double. Therefore, the weight of blood would be equal to half the overall weight and measure around 2.4g, which means it would contain 0.05g/ml multiplied
74
by 10ml, 0.5g of sulphur.

Assuming that the maximum amount of sulphur is transformed into SO
2
, it would produce 1g of sulphur dioxide. Therefore, if the guard room was 26m
3
, then this amount of sulphur would correspond to 13.5 parts per million (ppm) in the atmosphere. The American Conference of Governmental Industrial Hygienists have set the short-term exposure limit to fifteen minutes in an environment containing SO
2
to the measurement of 0.25ppm. This means that according to modern American health standards, no one should work unprotected in air with more than this amount of sulphur dioxide. Our 10cm
2
of paper can pump a maximum of nearly 13.5ppm into the atmosphere of a guard room, making it more than enough to affect the guards within.

Even halving that amount to allow for variation and minor ventilation in a medieval guard room, we can see that prolonged exposure to even such a small amount would cause the guards to suffer from irritation of the eyes, difficulty in breathing and possibly fatigue. Add to this the carbon monoxide and we can see that this strange tool might work – and of course we should not forget the ‘secret ingredient’!

Because we are unsure of the ventilation in the room, and because it is unknown what percentage of amino acids will turn into sulphur, the following list shows the range of emissions of sulphur dioxide which would disperse into a 26m
3
guardhouse. Remember, American health guidelines state that 0.25ppm is the maximum anyone should endure.

•
    50% of the sulphur becoming SO
2
would result in 5.18ppm in the guardroom.

•
    30% of the sulphur becoming SO
2
would result in 3.11ppm in the guardroom.

•
    10% of the sulphur becoming SO
2
would result in 1.04ppm in the guardroom.

It appears that a ninja would creep up to a guard house and drop this lit paper into a room of guards, who may not notice the smoke due to the candles and lamps. With some ventilation, the toxic compounds might escape the room, but after an unknown time of exposure the guardsmen would most likely feel unwell, have chest pains and perhaps feel the need to sleep.

The chemical analysis was for the blood-soaked paper alone, the insects and worms that were used historically are missing and they are the main ingredient.

Other forms beside the paper version exist, and consist of charred animal matter – toad milt, latrine larvae etc – which are then powdered and rolled in thin material, which is then cut into small ‘tablet’ sections and burnt upwind from an enemy, placed on an open windward side window of a building or inside a hole made on the windward wall of a building. Of course, experimentation would prove or disprove effectiveness.

The
Ninpo Hikan
scroll talks of a ‘medicine’ to keep you awake in times of need. It is one of the more outlandish ninja schemes and potentially deadly. The translation is paraphrased below:

To make this medicine, place mercury into a shell [and when laying down] put the mercury into your belly button and place paper on top. By doing this you will not sleep for five nights. However, if the Chi of the mercury gets into your belly it will cause you a great harm. Therefore, you should only perform this skill in dire need. If you do become ill then you should make a square of lotus leaves of 4 or 5 Sun across [approximately 15cm] and sit on it.

It is unclear whether the ninja takes the mercury out of the shell or he leaves it in the shell when he places it in his navel. Some shinobi may have contracted mercury poisoning from this venture – but did it keep them awake? The
Bansenshukai
uses the same method, however, it recommends bird excrement but without use of the shell.

Hunger Pills are ‘field rations’ for the ninja and consist of a selection of ingredients mixed into various size pills to be taken with a shinobi on a mission to give him energy and to keep hunger at bay.

The following table is a breakdown of the nutritional information found in one of the recipes from the
Bansenshukai
and displays the energy rates produced from each ingredient.
75

The chemical analysis of these pills indicates that every kilogram of the mixture produces an average output of around 2600 kilocalories,
79
and the total calorie count for the whole mixture above is approximately 4000 kilocalories.

The shinobi ‘Hunger Pill’ is featured in a selection of manuals in various forms and comes with information reassuring a ninja that these will help keep hunger at bay and most importantly, allow them to continue to function.

Today we are instructed that around 2000 calories are required to satisfy the needs of the average male and whilst it is tempting to try to use this number to produce a calculation to discover how many pills would be required to feed a ninja per day, there are so many variables have to be considered.

Firstly, the average Sengoku-period Japanese man may have been as small as five feet in height and will have been ‘wafer thin’ compared to our modern standards. This changes his nutritional needs from our point of view and by using a
standard
calorie calculator and assuming the man was engaged in light exercise, such as hiding and listening to the enemy or moving about at night, the calculation produces the figure of 1600 calories required to maintain his body weight at that size. This would require the ninja to eat just over 600 grams of the pills per day
80
to maintain his body weight.

Secondly, we don’t know his energy output and exercise pattern. The ninja may have been hidden in a hole, listening to the enemy for days on end making his calorie requirements minimal, or he could be taking a high path through barren mountains where food is scarce but his energy requirements are vast.

The third variable is that his situation is not modern and a ‘healthy average’ is a luxury – survival is the primary objective. A man may go without food for days in a wartime situation and eat meagre rations when he can get them, allowing weeks for the body to deteriorate and finally starve. A shinobi may be on the brink of starvation, he may be at his wit’s end, but still, in war some men will simply go on and on. The pills’ impressive energy output of over 2500 calories per kilogram represents a ninja aid that really does work, helping the ninja to survive without real food for an unknown period of time.

Two extraordinary statements are made in the
Bansenshukai
and the
Shoninki
, both of which refer to the ability to tell the time via observation of a switch between breathing through one nostril or the other. Natori states that ‘some people can perform this’ and Fujibayashi says ‘I have not mastered this.’ Unbeknownst to both of them, this skill was ahead of scientific observation by at least 200 years. What they are both referring to is in fact the biological phenomenon known as ‘The Nasal Cycle’. This cycle is the unconscious tendency of the human nose to switch between a priority air intake of either the left or right nostril that switches over at regular intervals. Dr Block and academic associates describe the cycle’s pattern in their research article ‘Unilateral Nostril Breathing’:

[The physician] Kayser first discovered a nasal cycle in 1895. Heetderks (1927) reported that the nasal cycle ranges between [a period of] 25 minutes and four hours and that it averages about two and a half hours. The autonomic nervous system probably regulates the cycle (Keuning, 1968; Stoksted, 1952, 1953). In this account, increased parasympathetic activation of a nostril causes the mucous membranes of that nostril to become engorged with blood. As a result, airflow decreases in it and the other nostril becomes more open.

What is most interesting is that the average time for the process is just above two hours but can be much less or much more. The difficulty that both Natori and Fujibayashi had is that they are trying to match the cycle to the contemporary Japanese hour system, which at the time averaged two hours but changed with the seasons. Modern research states that around 80% of the world population have an active nasal cycle and that they have variable cycle times. This means for a ninja to be able to use this skill he would have had to have had the cycle and had a similar rhythm to that of a two-hour period, around the average. Fujibayashi and Natori, if they had understood this fact, would have realised that each person has their own regular cycle and adjusted accordingly. Whilst the shinobi had this skill, they did not realise it could only work for certain people.

There are specific times for a ninja to infiltrate a mansion.