It was in 1909 that Thorn Smith, Professor of Analytical Chemistry, responded to urgent requests to produce unknown samples for his colleagues at the Michigan Agricultural College (now Michigan State University). Before long, his reputation for precision and honest value had him working evenings and weekends in his basement laboratory to produce enough samples for a growing number of colleges and universities throughout the United States.
Soon production facilities were established in Detroit where Professor Smith's unique and highly exacting standards together with many secret control, testing and mixing techniques combined to produce over a thousand unknowns of unsurpassed uniformity and quality. These standards have been scrupulously maintained and refined for over 100 years, and are the principle reason why Thorn Smith Laboratories is the leading supplier of analyzed materials for colleges and universities throughout the world.
With the present day trend to teach more theory in many labs, there has emerged greater demand for "simple" materials, rather than the ordinary or "commercial" products for teaching bench techniques as in earlier days. Formerly, so many complications arose in the use of commercial materials that the theory was obscured by the effort to reach a solution.
The high purity and predictable results of Thorn Smith analyzed materials has made their use in college and university labs a standard for consistently effective teaching and testing.
Professors and students find the convenience of Thorn Smith quantitative unknowns both satisfying and effective because they are working with materials that are uniform, precisely analyzed, specifically designed and manufactured for their use.
Now more than ever professors need and use Thorn Smith Quantitative and Qualitative Unknowns and Student Reference Standards. Why? Because they are cost effective, reliable and trouble free due to over 80 years of experience.
Professors specify and use Thorn Smith products because they know we are concerned about their students and supply products that are tested and proven. The idea behind Thorn Smith products is to help educate the students through learning by observing positive results, not trickery. Good learning results come from products that are carefully prepared, analyzed, and quality tested. Today, more so than in the past, professors have precious little time to make their own unknowns, let alone test them and be assured of their fairness to students. Our longevity in business is due to careful product preparation, upgrading of mixes, and a continuing effort to produce the best possible products.
First is "selection". By careful comparison of the many available raw materials, Thorn Smith carefully selects materials which are stable - as to air oxidation or reduction; as to interaction of components; as to taking up water in high humidity conditions or losing water in dry conditions (every component is checked by exposure to 100% and 0% humidity); as to physical problems such as caking (though this is very difficult to avoid with some materials). In addition, selection is governed by mixability and separation tendency.
Thus, selecting components for unknowns is half science and half art - and it is extremely important in the quality of the final product. This expertise comes only from decades of experience at Thorn Smith.
Second is "processing". Most raw materials have to be pulverized, classified (by sifting), and mixed by various methods. In addition, time of mixing is sometimes critical since some combinations of raw materials actually "de-mix" when mixed for long durations. Or some particles can build up an electrostatic charge or be worn down so small that they become air suspensions which settle out as a layer on top of a mix when the mixer is stopped. Therefore, like selection, the processing of raw materials is again about half science and half art - both of which are heavily dependent on years of experience.
Third is "analysis". Almost all of Thorn Smith's materials are sampled and analyzed using several different methods, to make sure that the unknown is suitable for a variety of analytical techniques. In some cases, the raw materials must be changed. For example, in preparing soluble sulfates unknowns, sodium sulfate, potassium chloride, and several other possibilities exist for active materials and diluents. Final student accuracy will depend not only on the care and method of analysis, but also on the amount of coprecipitation of the sodium, potassium, and chloride ions. Each year, many hours of literature and laboratory research are spent on these unknowns alone.
Thorn Smith also runs over 100 analyses for each new unknown series of 25 varieties. Thus, the more varieties of a particular unknown required by our customers increases our analysis work because each variety is treated as its own entity.
In addition to the selection, processing, and analysis of the the unknowns, the preparation of quality unknowns requires many special techniques, including the addition of either "anti-slip" or "lubricant" materials. Of course all of these additives are judged by their effect on the analysis or several different analysis schemes.
An extremely important factor in making decisions regarding selection, processing, and analysis are the reports from our customers. We are always looking for suggestions for improvement. Detailed notebooks are kept on every unknown, and every suggestion from the field is carefully considered and recorded. These suggestions lead to changes in our unknowns that make them more useful and easier to use. Thus, a great deal of thought, study, experience, and research goes into each unknown.
Thorn Smith also supplies answer sheets on all of their unknowns which contain reliable and accurate results. This makes it easy for students to analyze some unknowns in several different ways to compare methodology and results.
To prevent students from accumulating answer files, a new series of answer sheets with new compositions are prepared every few years. It is not unusual for students to misrepresent themselves in an attempt to obtain answer sheets for unknowns. Therefore, we adhere to some very strict policies regarding the release of answer sheets.
This is part of the extra effort that we expend to protect the answer sheets from falling into the wrong hands, and part of the service you would expect from us when purchasing our products.
Educators agree that students need "measuring sticks" to calibrate their equipment and volumetric standards. To give students reference standards of accuracy matching that of unknowns, Thorn Smith produces Student Reference Standards (see Student Standards Reference). Side-by-side analysis of these standards with Thorn Smith unknowns gives agreement of a few parts per ten thousand for many materials. Matching these accuracies provides a real challenge to even your best students.
Dry quals are also available. You can find more information about them in our Dry Quals Section.