The paper is focused on some aspects of experimental realism of Ian Hacking, and especially on his manipulability criterion of existence. The problem is here related to chemical molecules, the objects of interest in chemical research. The authors consider whether and to what extent this criterion has been applied in experimental practice of chemistry. They argue that experimentation on is a fundamental criterion of existence of entities in chemistry rather than experimentation with. Some examples regarding studies of structures of complex (...) compounds, taken from organic chemistry, are presented to support the authors' considerations. Chemists' laboratory practice depends strongly on the way that representations of entities on (or with) the experiments are used. The authors show that this point has not been given sufficient attention by the new experimentalists. (shrink)

The paper concerns the science of colors (die Farbenlehre) on which among others J.W. Goethe and W. Ostwald were focused. The first part of this essay describes the science of colors in the period from antiquity to late Renaissance. In the pre-scientific phase it was intervened with philosophical speculations as well with symbolism of magic, religions and customs. Since Newton’s time there are distinguished the colors of light and the colors of objects. J.W. Goethe’s Farbenlehre, discussed in the second part, (...) connects empirical studies and metaphysical vision of the light and colors. W. Ostwald, a distinguished chemist and philosopher-energetist, attempted to construct measurable Farbenlehre. He is a creator of a strict colors’ taxonomy, but his soul of artist (he was also a painter) “crept into” his study of colors. The discussion of Ostwald’s deliberations is contained in the third part of the paper. (shrink)

J. Such first introduced the notion of „complementary experiments”, referring to the decisive situations in science. The similar notions appears in the discussions of new experimentalists. For example, I. Hacking writes about complementarity of different types of microscopy, A. Franklin distinguishes technically good and conceptually important experiments, and P. Galison analyses examples of complementarity of two different approaches to the problem of cosmic radiation. In the article the notion of „complementarity” is extended as to cover the cases of complementarity of (...) method, complementarity of scientific teams etc. As an illustration it is used the case of discovering new type of carbon - called „fulleren”. (shrink)