The strange case of Dr. Petit and Mr. Dulong

The Dulong-Petit limiting law for the specific heats of solids, one of the first general results in thermodynamics, has provided Mendeleev with a powerful tool for devising the periodic table and gave an important support to Boltzmann's statistical mechanics. Even its failure at low temperature, accounted for by Einstein, paved the way to the the quantum mechanical theory of solids. These impressive consequences are even more surprising if we bear in mind that, when this law was announced, thermal phenomena were still explained using Lavoisier's concept of caloric and Dalton's atomic theory was in its infancy. Recently, however, bitter criticisms charging Dulong and Petit of `data fabrication' and fraud, have been raised. This work is an attempt to restore a more balanced view of the work performed by these two great scientists and to give them back the place they deserve in the framework of the development of modern science.Comment: Submitted to "Quaderni di Storia della Fisica", SIF (Italian Physical Society) publishe

L'Electrificació del canvi químic : els inicis al primer quart del segle XIX

La irrupció de la pila elèctrica de Volta en el territori de la química a principis del segle XIX va representar un repte important respecte a la concepció que es tenia del canvi químic. Les aportacions de Humphry Davy, Michael Faraday i Jöns Jakob Berzelius a aquesta empresa van inaugurar un nou discurs en la química que permetria tant interpretar de nou les reaccions químics com justificar les lleis que les regien.The arrival of Volta’s battery to the chemical world at the beginning of C19th started an important challenge for the traditional concepts of chemical change. The contributions of Davy, Faraday and Berzelius to this cause announced the arrival of a new chapter in chemistry that would allowed a new interpretation of chemical reactions and a justification of their laws

A Failed Encounter in Mathematics and Chemistry: The Folded Models of van ‘t Hoff and Sachse

Three-dimensional material models of molecules were used throughout the 19th century, either functioning as a mere representation or opening new epistemic horizons. In this paper, two case studies are examined: the 1875 models of van ‘t Hoff and the 1890 models of Sachse. What is unique in these two case studies is that both models were not only folded, but were also conceptualized mathematically. When viewed in light of the chemical research of that period not only were both of these aspects, considered in their singularity, exceptional, but also taken together may be thought of as a subversion of the way molecules were chemically investigated in the 19th century. Concentrating on this unique shared characteristic in the models of van ‘t Hoff and the models of Sachse, this paper deals with the shifts and displacements between their operational methods and existence: between their technical and epistemological aspects and the fact that they were folded, which was forgotten or simply ignored in the subsequent development of chemistry

Is coherence catalytic?

Quantum coherence, the ability to control the phases in superposition states is a resource, and it is of crucial importance, therefore, to understand how it is consumed in use. It has been suggested that catalytic coherence is possible, that is repeated use of the coherence without degradation or reduction in performance. The claim has particular relevance for quantum thermodynamics because, were it true, it would allow free energy that is locked in coherence to be extracted $\textit{indefinitely}$. We address this issue directly with a careful analysis of the proposal by $\AA{}$berg. We find that coherence $\textit{cannot}$ be used catalytically, or even repeatedly without limit.Comment: 23 pages with 2 figure

Eilhard Mitscherlich und Justus von Liebig

Also includes the maps Blanch Bay: Greet Harbour; New Britain: Kokopo; New Britain: Massava Bay; New Britain: Ataliklikun Bay Unter KambeiraPublished at the Admiralty 12th Sept 1899 under the Superintendence of Rear Admiral Sir W.J.L. Wharton, K.C.B. F.R.S. Hydrographer. Reproduced by Hydrographic Branch, Sydney by permission of the Hydrographer

‘A devotion to the experimental sciences and arts’: the subscription to the great battery at the Royal Institution 1808–9

A significant but neglected theme in the history of British science in the nineteenth century is the funding of institutional research. The subscription to the ‘great battery’ at the Royal Institution in 1808 and 1809 provides the first instance of named individuals prepared to commit themselves to the provision of apparatus to be used for research in the new field of electrochemistry. This paper analyses the subscribers who were deemed to be ‘enlightened’ and whom Humphry Davy subsequently described as ‘a few zealous cultivators and patrons of science’. Using information from the subscription list, a distinction is made between the individual subscriptions pledged and the sums actually paid. In contextualizing the subscription, insights are provided into the Royal Society, the contemporary scientific community and the politics of metropolitan science. The voltaic subscription represents an early example of the repercussions of the nature of research funding for institutional finances and governance

Organosilicon reagents in natural product synthesis

Berzelius, the Swedish chemist in 1807 introduced the term 'org. compds.' as those substances derived from once living organisms. Carbon exhibits the property of catenation (formation of chains) and forms a plethora of compds. on earth. Silicon, which is placed below carbon in the periodic table, does not exhibit this property. A brief account of some of the several reagents and classes of compds. encountered in organosilicon chem. is presented

Superação do vitalismo e o imparável desenvolvimento da síntese orgânica

A síntese orgânica representou um marco capital no História do Química, conduzindo ao fim da filosofia vitalista que considerava que as substâncias constitutivas dos animais e das plantas eram de natureza diferente dos corpos minerais, não obedecendo as mesmas leis, nem podendo ser feitas em laboratório. Quase dois séculos volvidos, a filosofia emergente e, agora, a de uma síntese verde, ambientalmente mais sustentável