Peter Desaga

Peter Desaga (1812 – 1879) was a instrument maker at the University of Heidelberg who designed, and built, the first Bunsen burner. There is little information available about Desaga’s early life; according to German Wikipedia Desaga’s father, Michael, was a teacher and Desaga received his training as a mechanical engineer, lens grinder, and calibrator in Heidelberg, Paris, and London. In 1840 Desaga started a scientific apparatus manufacturing firm which he had named after his son ‘C Desaga’. The company later became known as Desaga GmbH and in 2014 became part of the Sarstedt group. The majority of what we know about Desaga’s life is in relation to his work as a technical collaborator of Robert Bunsen, particularly in the development of the Bunsen burner.

Robert Bunsen (1811-1899) was a passionate teacher and experimenter. He arrived in Heidelberg in 1852 to take up the position of Professor of Chemistry. Coincidentally Heidelberg was supplied with coal-gas a year later (much later than in most British towns) so when Bunsen was having a new laboratory built he insisted on including the necessary piping for this gas.

Until that point the primary source of heat and light in laboratories had not really changed since the time of the alchemists. Experimenters had to wrestle with charcoal and coal furnaces, alcohol/spirit lamps, and candles if they wanted to heat (or see!) their experiments. Experiments with gas burners had started in the 1820s when gas lighting had first appeared in the larger European cities and towns. Michael Faraday was one of the first to described a burner in his book, Chemical Manipulation in 1827. Later, other burner designs were suggested, the most popular being a “gauze burner” which worked on a similar principle to the Davy’s lamp. Unfortunately, the resulting flame was diffuse, relatively cool, and suffered from excessive flickering and coloration due to contaminates on the metal screen.

Bunsen’s original design.
Bunsen’s original design. (from J. Chem. Ed., 77, 5, p558-559, 2000)

Bunsen wanted a high temperature, virtually colorless, soot-free flame of constant size for his work in photochemistry. He realised that the way to achieve this was to premix  the gas and air prior to combustion. It seems that he took his ideas to the university instrument maker, Peter Desaga. Desaga experimented with the design, trying tubes of all sizes and varying the diameter of the air inlet. It was Desaga who developed the design shown above in 1855.

Desaga manufactured 50 for Bunsen’s newly constructed laboratory and started selling them commercially. Such was the revolutionary nature of the new burner there was worldwide demand. Despite this, Bunsen refused to patent the design and so others started copying Desaga’s design. Some even tried to claim the invention as their own and to patent very similar designs. As early as 1855 a Berlin based firm were claiming the design as their own and Desaga had to sent a note to the Dingler Polytechnische Journal refuting the allegation. To support Desaga Bunsen gave him a written declaration that it was Desaga’s innovative design based on a principle outlined by Bunsen.

Outside of the university Desaga was clearly a well respected man. He became the first fire chief of the Heidelberger fire brigade in 1852. He then went onto become a member of the municipal council in 1855.

Adapted Bunsen burner for studies with the blowpipe
Adapted Bunsen burner for studies with a blowpipe (1960). (from J. Chem. Ed., 33, 1, p.20-22, 1956)

Bunsen did not publish an account of the burner until two years later in a 1857 paper written with his colleague Roscoe. He wrote, “If the tube…is screwed into the cylinder, and the city gas is allowed to flow into it…, it sucks in so much air through the openings d that it burns at the mouth of the tube e with a nonluminous, perfectly soot-free flame.” He does not mention Desaga in that paper.

Gustav Kirchhoff and Robert Bunsen
Gustav Kirchhoff (left) and Robert Bunsen (right) c.1850

Desaga also built one of the first spectrometers. In 1859, Bunsen and Kirchhoff were working in the new field of spectroscopy. They used a small spectrometer (shown below) that was build by Desaga to determine the chemical composition of bodies remote in space and identify new elements. The clean and consistent light produced by the Bunsen burner was key to the success of this work.

Sketch of an early spectroscope
Sketch of an early spectroscope. (from J. Chem. Ed., 77, 5, p558-559, 2000)

The Bunsen burner we see in laboratories today has two larger holes in the burner tube with a rotatable cuff to open or cover them. This design replaced the four holes in the cubical base sometime in the 19th century and it is probable that Peter Desaga was again involved in this innovative design improvement.

For over 150 years now Bunsen burners have sat on the benches of almost every scientific laboratory in the world. While their use has slowly dwindled they played a key part in scientific progress during that time, and while their name may remember Robert Bunsen, their design will always be a tribute to Peter Desaga.

Further reading

I can find very little information about Desaga’s life and no image of him – if anyone has any further information please let me know.  There are some very interesting histories of the Bunsen burner – a few of these are listed below.

  • Lockemann, G, The centenary of the Bunsen burner, Journal of Chemical Education, 33(1), 1956.
  • Kathryn R. Williams, A Burning Issue, Journal of Chemical Education, 77(5) 2000
  • Russell, C.A., Bunsen without his burner, Physics Education, 34(5) September 1999
  • Jensen, W.B., The origin of the Bunsen Burner, Journal of Chemical Education, 82(4), p.518, 2005

 

 

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