118 PROFESSOR HARTING, 



On the Artificial Production of some of the principal 

 Organic Calcareous Formations. By Professor 

 Harting, of the University of Utrecht. (Preliminary 

 communication.) ^ 



The following pages contain only an abridged report^ of a 

 series of researches, undertaken with the view of producing, 

 independently of living organisms, certain calcareous forma- 

 tions, which are met with in animals as integral parts of 

 their skeleton, and this by causing calcium carbonate and 

 phosphate to combine, in the nascent state, with organic 

 substances. 



An essential condition of attiiining this end is to follow 

 nature as precisely as possible in the tranquillity and slow- 

 ness of her operations. This result may be obtained by 

 placing in the liquid containing the organic matter, with 

 Avhich the calcari^ous salts, as soon as formed, are expected to 

 combine, salts which by their double decomposition produce 

 insoluble salts of calcium. 



With this object the salts, in the solid state, are placed in 

 the liquid at a certain distance one from another, either free 

 to mix or else separated by a membrane. The liquids em- 

 j)loyed were albumen, solution of gelatine, a mixture of these 

 two substances, blood, bile, mucus from Arion rufus, tissue 

 of the umbrella of Aurelia aurita, and, finally, the liquor 

 obtained by triturating chopped-up oysters in a mortar. 



The salts which were intended by their mutual reaction to 

 produce insoluble calcareous salts were, on the one hand, 

 calcium chloride, calcium nitrate, calcium acetate, magnesium 

 chloride, and magnesium sulphate ; and, on the other hand, 

 sodium bicarbonate, potassium carbonate, sodium phosphate, 

 and ammonium phosphate. 



It is clear, from the method in which the experiments 

 were conducted, that the mixture of salts could only be 

 effected Avith extreme slowness and by diffusion. Thus, 

 several weeks elapse, in most cases, before the formation of 

 the calcareous combinations is completed and the experiment 

 terminated. 



By this method a considerable number of forms are de- 



• Translated into French from the Dutch original by Professor Edouard 

 Van Beneden, and coirimuuicated by the translator. 



- A detailed description will be given in a memoir which is about to 

 appear in the publications of the Royal Academy of Amsterdam. It will be 

 shortly sent to press under the title of ' Researches in Synthetical Mor- 

 phology, on the Artificial Production of Some Organic Calcareous For- 

 mations.' 



