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Do You Conduct Your Own Experiments Like Sherlock?

Sherlock Using Riding Crop

In the series opener, we find Sherlock Holmes performing a task that most of us would never find ourselves doing. He has a riding crop in his hand and is beating a cadaver. While the situation presented is rather comical, I watched this and thought, "of course Sherlock would be doing this."

In the original story, we find Sherlock conducting an experiment with Hemaglobin when he meets Watson.

He says, “The question now is about hoemoglobin. No doubt you see the significance of this discovery of mine?”

“It is interesting, chemically, no doubt,” I answered, “but practically——”

“Why, man, it is the most practical medico-legal discovery for years. Don’t you see that it gives us an infallible test for blood stains. Come over here now!” He seized me by the coat-sleeve in his eagerness, and drew me over to the table at which he had been working. “Let us have some fresh blood,” he said, digging a long bodkin into his finger, and drawing off the resulting drop of blood in a chemical pipette. “Now, I add this small quantity of blood to a liter of water. You perceive that the resulting mixture has the appearance of pure water. The proportion of blood cannot be more than one in a million. I have no doubt, however, that we shall be able to obtain the characteristic reaction.”

As he spoke, he threw into the vessel a few white crystals, and then added some drops of a transparent fluid. In an instant the contents assumed a dull mahogany colour, and a brownish dust was precipitated to the bottom of the glass jar.“Ha! ha!” he cried, clapping his hands, and looking as delighted as a child with a new toy. “What do you think of that?”

“It seems to be a very delicate test,” I remarked.

“Beautiful! beautiful! The old Guiacum test was very clumsy and uncertain. So is the microscopic examination for blood corpuscles. The latter is valueless if the stains are a few hours old. Now, this appears to act as well whether the blood is old or new. Had this test been invented, there are hundreds of men now walking the earth who would long ago have paid the penalty of their crimes.”

“Indeed!” I murmured.

“Criminal cases are continually hinging upon that one point. A man is suspected of a crime months perhaps after it has been committed. His linen or clothes are examined, and brownish stains discovered upon them. Are they blood stains, or mud stains, or rust stains, or fruit stains, or what are they? That is a question which has puzzled many an expert, and why? Because there was no reliable test. Now we have the Sherlock Holmes’ test, and there will no longer be any difficulty.”

In this section of the story, we find that Holmes is deep at work on his own personal experiment. Throughout the stories we often find Holmes conducting various experiments or spending time trying to figure out the solution to some new problem.

In modern criminal investigation, there are three sequential stages used to determine blood stains: search and orientation, confirmation, and individualization. This first involves determining if the presumed blood stain contains any biological fluid. Then the stain is sifted to determine the type of biological fluid. If the fluid is of use, it will be analyzed genetically. There are a number of reagents used:

  • Luminol (3-aminophthalhydrazide) (Merck)

  • Sodium perborate (Panreac)

  • Sodium carbonate (Panreac)

  • Distilled water

  • Bluestar[R] Forensic

  • Hexagon OBTI[R] test

  • Rapid Stain Identification[TM]-Blood (RSID[TM]-Blood)

  • Sodium percarbonate (Panreac)


I gather that if Holmes was a real person, he would be able to develop a test to discover blood stains that had dried. In the Study in Scarlet, Watson lists Holme's knowledge of chemistry to be "profound." What does this mean?

Many fans love Sherlock for his ability to think and reason. But if we consider a number of his choices in life, like the one to pursue a profound knowledge of chemistry, it shouldn't surprise us that he can solve complex cases. He has invested a large amount of his time studying something extremely useful to his field of study. Every aspect of his life, from listening to and receiving clients into 221B to delivering the final deductions/conclusions, we find that Holmes is willing to go all in when it comes to developing his skills.

He could have used the old "Guiacum test" which he deemed as "very clumsy and uncertain." But instead, he chooses to create his own experiment to reach a better result for a question that is constantly presented to him. What's the takeaway?

  1. Holmes wants to reach solid and complete conclusions (Hence the need to improve the test)

  2. Holmes recognizes the value of improving on old methods and procedures.

  3. He is willing to invest time learning skills that will further his field of study and his ability to reach accurate conclusions.

Sherlock Holmes didn't shy away from striving to reach complete conclusions and you shouldn't either. Don't be daunted by mental work. It is easy to allow confirmation bias to creep into your thinking. When we want something to be true, we often believe it. It's definitely easier to reach conclusions we want to believe rather than continuing to search for more accurate or concrete conclusions. Do tasks that require mental toughness. Play chess, go for long runs, look for opportunities to challenge your thinking, pushing it past its normal limits.

Sherlock recognized that there was a system in place to detect Hemoglobin but he felt it was insufficient. Look for procedures and methods in your field of study that may be lacking and find ways to improve them. This may require you to create your own versions of the method or experiment the process with the aim of improving upon it. Don't shy away from the hard work that may come with this step.

If you want to reach more accurate conclusions when a problem presents itself, you may have to spend more time invested in your core knowledge. Sherlock spent a non-disclosed amount of time studying chemistry, but he must have invested a significant amount of time doing so. While we don't always see Holmes using his knowledge of chemistry , he likely used this skill daily to improve it. Could you invest time learning something to enhance your skills? Sign up for classes or search for information that will be useful to your skill set. Make sure it is quality information you study.


So what can you do to create your own experiments? I read through a MIT's Experimental Design webpage and they offer some really good insights into creating experiments. Here is the link: Experiment Design.

Some basics for creating your own experiments include:

  • Observe - What do you see, smell, taste, touch, or hear?

  • Ask a scientific question. "What type of reagent will display a specific reaction when it encounters blood?"

  • Hypothesize - A hypothesis is a tentative answer to a question. "If I wash a blood stain with sodium carbonate wash solution I expect the stain to..."

  • Identify the variables - A variable is any factor that may differ or change in your experiment. There are constant/controlled variables which stay the same during the experiment, like the actual blood stain being studied. Then there are independent and dependent variables. An independent variable is one that you as the experimenter control. For example, you may choose to change the temperature of the reagent solution. A dependent variable is a variable that responds to the change in the independent variable.

  • Control - The experiment needs a control. A control is a group in which the independent variable does not change. These are used to detect or measure the influence of unanticipated factors. They act as a baseline or reference point.

  • Repeat - Repeat the trial/experiment to ensure reliability. Additionally, try to test your independent variables one at a time. Keep other potential variables constant and use the control group.

  • Observe and Hypothesize again if necessary.


You may not need to create experiments daily but I think it is always cool to spend time trying experiments, even if you already know the conclusion. They have some really good benefits. They help you get into the mind space of using the scientific method and can be really enjoyable. Here are a couple of experiments that you can perform with your family and friends. Like always - love to learn again.

Works Cited:

Castello, Ana, et al. "An alternative to the human hemoglobin test in the investigation of bloodstains treated with active oxygen: the human glycophorin a test." The Scientific World Journal, vol. 11, 2011, p. 907+. Health Reference Center Academic, Accessed 1 Dec. 2018.

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