Since its very beginning, physicsPhysics has enjoyed the position of the only science properScience Proper among the different branches of sciences, even for social ones. There is a good justification for this. The method of modern science, worked out by Galileo[aut]Galileo, is strongly based on physics (mechanics). Actually, scienceScience started as mechanics. It is not clear, however, whether being a firm foundation for the whole of science would make the best model for any kind of science. There is science that is physicsPhysics-like and has to be such and science that is not physics-likePhysics-Like and perhaps does not have to be like that. It is interesting that there is also a scienceScience that is partly physics-like and partly not physics-like, namely chemistryChemistry. It is the former as far as it looks for the lawsLaw of nature, i.e. the lawLaw of periodicity, and it is the latter as long as it deals with substances (or stuff). The current essay takes a deeper look into the similarity and difference between physicsPhysics and chemistryChemistry from the historical and philosophical perspective. The analysisAnalysis of the dual character of chemistryChemistry from the historical perspective allows proposing a more solid historical justification to the special position of physicsPhysics as the only science properScience Proper.