China is home to many discoveries. The case with chemical poisonous substances is no exception - du yao yan qiu, or "a ball of poisonous smoke", is mentioned in the treatise "Wu jing zong-yao". Even the recipe for one of the first chemical warfare agents has survived:
Sulfur - 15 lians (559 g)
Saltpere - 1 jin 14 lian (1118 g)
Aconita - 5 lians (187 g)
Croton tree fruit - 5 lians (187 g)
Belens - 5 lians (187 g)
Tung oil - 2.5 liang (93.5 g)
Xiao Yu oils - 2.5 liang (93.5 g)
Chopped charcoal - 5 liang (93.5 g)
Black resin - 2.5 liang (93.5 g)
Arsenic Powder - 2 liang (75 g)
Yellow wax - 1 liang (37.5 g)
Bamboo Fiber - 1 liang 1 fen (37.9 g)
Sesame fiber - 1 liang 1 fen (37.9 g)
Schoolboy SA in his work "Chinese pre-fire artillery" describes the use of chemical weapons and the consequences: "…" balls of poisonous smoke "rushed from fireballs or attached to the arrows of large easel arcballista. The ingestion of poisonous smoke into the respiratory tract of a person caused profuse bleeding from the nose and mouth. Unfortunately, indications of other damaging properties of the projectile are lost in the text of the treatise that has come down to us, but, obviously, an intense flash of gunpowder led to the rupture of the shell under the pressure of gases and the scattering of particles of the poisonous contents of the ball that did not have time to burn. Once on human skin, they caused burns and necrosis. There is no doubt that the main purpose of the balls, despite the presence of gunpowder in them, was precisely the poisonous effect. Consequently, they were the prototype of the later chemical projectiles. " As you can see, a person learned to kill with the help of chemistry much earlier than he thought of defending himself. The first examples of isolation systems did not appear until the middle of the 19th century, and one of them was a Benjamin Lane respirator from Massachusetts, equipped with a compressed air supply hose. The main purpose of his patented invention, Lane saw the ability to enter buildings and ships filled with smoke, as well as into mines, sewers and other rooms in which poisonous gases have accumulated. A little later, in 1853, the Belgian Schwann created a regenerative respirator, which became the basic design for isolation systems for many years to come.
Regenerative respirator Schwann "Aerofor". Description in text
The principle of operation is as follows: air from the lungs through the mouthpiece 1 passes through the exhalation valve 3 into the exhalation hose 4. The next step, the air enters the regenerative or absorption cartridge 7, which contains two chambers with granular calcium hydroxide (Ca (OH)2impregnated with caustic soda (NaOH). Carbon dioxide in exhaled air passes through dry absorption cartridges, combines with calcium hydroxide, transforming into carbonate, and alkali plays the role of a moisture absorber and an additional reagent with carbon dioxide. The air purified in this way is additionally supplied with oxygen from the cylinders 8 through the regulating valve 10. Then the air ready for breathing is sucked in by the force of the lungs through the hose 5, the breathing bag 6 and the inhalation valve 2. The user can at any time regulate the amount of oxygen supplied to the breathing mixture using valve. Oxygen is stored in 7-liter cylinders at a pressure of 4-5 atmospheres. The Schwann isolating respirator with a weight of 24 kg made it possible to stay in an atmosphere hostile to breathing for up to 45 minutes, which is quite a lot even by modern standards.
An advertisement for the Lacour apparatus, 1863. Source: hups.mil.gov.ua
The next was A. Lacourt, who received a patent in 1863 for an improved breathing apparatus consisting of an airtight bag with a rubber pad. Usually, firefighters used the Lakura breathing apparatus, fixing it on the back with straps with a waist belt. There was no regeneration: air was simply pumped into the bag and fed into the lungs through the mouthpiece. There was not even a valve. After filling the bag with air, the mouthpiece was simply plugged with a cork. However, the inventor nevertheless thought about comfort and attached a pair of glasses, a nose clip and a whistle, which emits a sound when pressed, to the set. In New York and Brooklyn, the firefighters tested the novelty and, appreciating it, adopted it.
By the second half of the 19th century, the Siebe Gorman Co, Ltd company from Great Britain became one of the trendsetters for insulating gas masks. So, one of the most successful was the Henry Fleiss apparatus, developed in the 1870s, which already had a mask made of rubberized fabric that covered the entire face. The versatility of Fleis's design was in the possibility of using it in diving business, as well as in mine rescue operations. The set consisted of a copper oxygen cylinder, a carbon dioxide adsorbent (regenerative cartridge) based on caustic potassium and a breathing bag. This device really became famous after a series of rescue operations in English mines in the 1880s.
Fleis diving breathing apparatus. Source: hups.mil.gov.ua. 1. Dorsal breathing bag. 2. Respiratory tube. 3. Rubber half mask. 4. Cargo. 5. Compressed oxygen cylinder
Breathing pattern in the Fleis apparatus. Source: hups.mil.gov.ua. 1. Oxygen bottle. 2. Breathing bag. 3. Absorber box. 4. Rubber tube. 5. Half mask. 6. Exhalation tube. 7. Exhalation valve. 8. Inspiratory valve. 9. Inspiratory tube
However, the oxygen cylinder was small, so the time spent under water was limited to 10-15 minutes, and in cold water, due to the lack of a waterproof suit, it was generally impossible to work. The development of Fleis was improved in 1902, when they equipped it with an automatic oxygen supply valve and installed durable oxygen cylinders at 150 kgf / cm2… The author of this development, Robert Davis, also transferred the isolation apparatus for convenience from the back to the user's chest.
Davis' rescue apparatus. Source: hups.mil.gov.ua
The Americans Hall and Reed also worked on the improvement in 1907, equipping the regenerative cartridge with sodium peroxide, which is capable of not only absorbing carbon dioxide, but also releasing oxygen. The real crown of the technical creativity of Robert Davis was the rescue apparatus - an oxygen rebreather of the 1910 model, which allowed submariners to leave the ship in an emergency.
In Russia, work was also underway on self-contained breathing apparatus - for example, warrant officer of the Navy A. Khotinsky in 1873 proposed an apparatus for autonomous operation of a diver with a closed breathing cycle. The suit was made of double lightweight fabric, additionally glued with rubber, which made it possible to work in rather cold water. A half-mask made of copper with a glass visor was worn on the face, and tanks with oxygen and air were responsible for breathing. Khotinsky also provided for a system for cleaning exhaled air from carbon dioxide using a cartridge with "sodium salt". However, there was no place for the development of the midshipman in the domestic fleet.
Dräger's mine respirator 1904-1909: a - Dräger's mouthpiece (side view); b - Dräger's helmet (front view). Source: hups.mil.gov.ua
Since 1909, the German company Dräger has entered the first roles in Europe as a developer and supplier of self-contained respirators and gas masks. In the matter of rescuing miners and mine workers, the devices of this company have become so popular that even the professional name of rescuers "drägerman" has appeared. It was the products of Dräger that the Russian Empire, and later the USSR, were actively purchasing and using in their own mining industry. Draeger's 1904-1909 mine respirator, which existed in the mouthpiece and helmet versions, became a visiting card. In fact, this was a deeply modernized apparatus of the Schwann system with separately stored regenerative cartridges with caustic soda and twin oxygen cylinders. By and large, Dräger products (as well as similar devices of the German "Westphalia") were not something out of the ordinary - a well-thought-out advertising campaign and marketing gimmicks played a huge role in the prevalence. Oddly enough, the decisive role in the subsequent modernization of Draeger's devices was played by Dmitry Gavrilovich Levitsky, a Russian engineer and specialist in the field of fire safety of mining enterprises.
Dmitry Gavrilovich Levitsky (1873-1935). Source: ru.wikipedia.org
The development of a new isolation apparatus was prompted by the horrific consequences of the explosion of methane and coal dust at the Makaryevsky mine of the Rykovsky coal mines on June 18, 1908. Then 274 miners died, and 47 were seriously injured. Dmitry Levitsky personally participated in the rescue work, carried several people out of the lesion, and even got carbon monoxide poisoning.
Coffins with the dead on June 18, 1908 at mine No. 4-bis of the Makarievsky mine of the Rykovsky coal mines and the funeral procession. Source: infodon.org.ua
Workers of the rescue cooperatives of the Rykovsky mines. Source: infodon.org.ua
In the design proposed by the engineer after this tragedy, it was proposed to remove carbon dioxide by freezing with liquid air. To do this, exhaled air was passed through a five-liter reservoir with liquid contents, and carbon dioxide settled to the bottom. It was the most advanced design at that time, allowing it to work in emergency conditions up to 2.5 hours, and at the same time it was distinguished by a relatively low weight. The Levitsky apparatus was tested, but the author could not obtain a patent for it, which was used by German engineers, introducing the engineer's ideas into their isolation apparatus. They learned about Levitsky's work after his article in one of the industry magazines, in which he criticizes existing devices and describes his idea with liquid air. The development of the Russian engineer went down in history as the oxygen "revitalizing" apparatus "Makeevka".
Oxygen "revitalizing" apparatus of Levitsky "Makeevka". Source: hups.mil.gov.ua
In 1961, Bulvarnaya Street in Donetsk was renamed into D. G. Levitsky and erected a memorial sign there.
