Gas Inhalation
One perspective on this remarkable discovery is to view it as
the culminating event of nearly 75 years of experimentation on the therapeutic use
of inhaled gases and vapors. The chemist of the late 16th century was looked on
as a blight on society, a person who worked with vile-smelling substances and whose
clothes were covered with stains and burns. These attitudes began to change in the
17th and 18th centuries, when the chemists discovered that air was not a simple substance
but a combination of different airs, all following certain physical laws. Jean Baptiste
van Helmont (1577–1644) invented the word gas
(from the Greek chaos) to describe an uncontrollable
substance that was liberated when acid was added to limestone.[112]
Robert Boyle[113]
(1627–1691), Jacques Charles
(1746–1823), and John Dalton (1766–1844) outlined the basic properties
of gases, and these laws accelerated the study of combustion, respiration, and the
transmission of sound. Of particular importance to our history is the law governing
the transfer of gases into liquids, proposed by William Henry[114]
(1775–1836) in 1803. Henry's law stated that the amount of gas absorbed by
a liquid is proportional to the pressure of the gas above the liquid, provided no
chemical reaction occurs.
Joseph Priestley and the Swedish chemist Carl W. Scheele (1742–1786)
performed the first investigations on gas inhalation. Scheele, the co-discoverer
of oxygen, nearly killed himself by experimenting with inhalation of hydrocyanic
acid, one of the several gases he discovered.[11]
Priestley played a significant role in the identification of elemental gases and
advocated inhalation of "dephlogisicated air" (i.e., oxygen) for various medical
conditions. He wrote in 1776 that after inhalation of dephlogisicated air, "I fancied
that my breast felt peculiarly light and easy for some time afterwards. Who can
tell that in time, this pure air may become a fashionable
article in luxury. Hitherto only two mice and myself have had the privilege of breathing
it."[10]
Unsanitary living conditions in the late
18th century had led to a preoccupation with the evils and disease-producing attributes
of putrid air. The corollary was that pure airs, even "fixed air" (i.e., carbon
dioxide), the same gas described by van Helmont and rediscovered by Joseph Black
[115]
(1728–1799), might promote health.
As a result of the growing scientific interest in various types
of "airs," popular medical treatments involving gas inhalation evolved. Health resorts
were popular attractions and financially successful because of their use by prominent
members of society. One important "pneumatic" spa was located at Clifton, near Bristol,
England, where Thomas Beddoes[116]
(1760–1808)
furnished airs for therapeutic use and funded research on the manufacture and use
of gases. Nitrous oxide, a gas codiscovered by Priestley and Joseph Black, was by
then considered to be a dangerous gas, following the pronouncement by the American
chemist Samuel Latham Mitchill that the gas was the "principle of contagion" and
if breathed would "spread plague." The young scientist Humphry Davy conducted research
on nitrous oxide at the Beddoes institute and, undaunted by these pronouncements,
made several important observations. He inhaled nitrous oxide and noticed that it
provided relief from the pain caused from an erupting wisdom tooth. In 1800, he
wrote: "As nitrous oxide in its extensive operation appears capable of destroying
physical pain, it may probably be used with advantage during surgical operations
in which no great effusion of blood takes place."[117]
Davy was not a surgeon, and clinicians overlooked his suggestion
at the time. He resigned his position at the Beddoes Medical Pneumatic Institute
in 1801 and moved to London to lecture at the newly founded Royal Institution of
Great Britain. Davy was only 20 years old when he performed the studies on nitrous
oxide, and his subsequent, highly successful career took him into other areas of
scientific study that led to the discovery of the elements potassium, sodium, calcium,
barium, magnesium, strontium, and chlorine. He was knighted in 1812, became President
of the Royal Society in 1820, and never returned to develop his promising early thoughts
on nitrous oxide analgesia. Regrettably, he left no students to continue these studies,
although his successor at the Royal Institute, Michael Faraday (1791–1867),
briefly experimented with ether inhalation and observed that its "effects were similar
to those occasioned by nitrous oxide."[118]
The first research specifically directed toward an effective method
for providing pain-free surgery was made by a physician working in the village of
Ludlow, Shropshire in northern England. Henry Hill Hickman (1800–1830) was
a practicing surgeon who investigated the use of carbon dioxide to induce insensibility
in animals. Because of the widespread interest in inhalation therapy at the beginning
of the 19th century, it is not surprising that Hickman used an inhaled gas. Unfortunately
for him, he used the wrong gas, because if he had selected nitrous oxide, which was
known to produce analgesia, his results might have achieved further attention. Although
he published his work in 1824 in a private letter to T. A. Knight,[119]
Hickman failed to find any support from his colleagues in England or France, and
he died at an early age without recognition.
Although pneumatic spas such as the Beddoes Institute were short-lived,
a lingering interest in gas inhalation persisted in the form of traveling amusement
shows that welcomed members of the audience to experience the altered sensations
induced by ether or nitrous oxide inhalation. A young ex-merchant marine, Samuel
Colt (1814–1862), learned how to produce nitrous oxide from the chief chemist
at a textile factory where he had occasional work. Colt needed cash to secure a
patent on a new type of handgun that he had invented while at sea. The gun featured
a rotating cylinder that advanced up to six new cartridges when the hammer was cocked.
In the early 1830s, Colt traveled from village to village along the East Coast of
North America selling whiffs of nitrous oxide for 25 cents. The enterprise was highly
successful, and he used his accumulated funds to patent his new revolver in 1835.
The gun was used by the U.S. military in the U.S.-Mexican War, and during the following
decades, the Colt six-shooter became one of the legends of the Wild West of North
America and made Samuel Colt one of the wealthiest men of his time.
 |
