SOS ANNUAL OF SCIENTIFI DISCOVERY. 



ral with bisulphate of potash. Phosphoric acid is always present, and so 

 also is chlorine, which constitutes about 3-1000ths of the lava examined. 

 Chlorine is also found in the rocks of Puraci, in an amphigenous stratum of 

 the Somma, and in a slag-like stratum of the same mountain. The felspar 

 of the lavas of Vesuvius appears to be amphigenous, and is distinguished 

 from that of the Somma by its only containing traces of soda; while in the 

 felspar of the lava of 1855, the oxygen of the soda is in the proportion to that 

 of the potash as 2'09 : 1. This proportion in the mineral of Fasso-grar.dc is 

 8'21 : 1, and in the amphigenous perfect crystals which were thrown out of 

 the volcano on the 22d of June, PG7 : 1 according to Damour. 



ON THE EMPLOYMENT OF SULPHURET OF CARBON FOR INDUSTRIAL 



PURPOSES. 



In a communication to the French Academy on the above subject, M. Dictz 

 commences by stating, that in 1840 the price of sulphuret of carbon was 

 as high as from fifty to sixty francs the kilogramme ; but that soon after- 

 wards he reduced its price so greatly that in 1848 it sold at eight francs the 

 kilogramme for the purpose of vulcanizing India-rubber. At present, with 

 an apparatus composed of three retorts, he is able to manufacture the im- 

 mense quantity of 500 kilogrammes of sulphuret of carbon in twenty-four 

 hours ; although scarcely a year ago, with the same furnace, the same re- 

 torts, and the same amount of fuel, he could only produce 150 kilogrms. in 

 the same time. The product now costs him only 50 centimes the kilo- 

 gramme, and he has no doubt that, by operating on a larger scale, it might 

 soon be sold at 40 francs per 100 kilogrms. As, however, this substance has 

 at present only a very limited employment in the vulcanization of India- 

 rubber, the author having a large quantity on his hands, naturally desired to 

 find some other purpose to which it might be applied ; and considers that he 

 has discovered one of the greatest importance, namely, the extraction of fatty 

 matters. 



He states that Paris daily produces 30,000 kilogrms. of bones, which are 

 collected by the chiffoniers and carried to the manufactories of ivory-black 

 and gelatine. Here they are sorted, some being devoted to the production 

 of ivory-black, others of gelatine, whilst some are sold to the workers in 

 bone. The greater part of them (25,000 kilogrms. daily) arc employed in 

 the manufacture of ivory-black ; but these undergo a preliminary treatment 

 for the extraction of their fatty matter. The bones are broken and boiled 

 with water, for about three hours, in large caldrons ; the fat floats on the 

 surface and is skimmed off ; the bones are taken and thrown into a heap, to 

 undergo a kind of fermentation, in which the production of heat induces a 

 state of desiccation which fits the bones for calcination. 



In these operations the bone undergoes a great alteration : the long boil- 

 ing in water dissolves a great portion of the gelatine, which is necessary for 

 the production of a good black : and the fermentation and long exposure to 

 the air causes the almost total destruction of the animal matter, so that a 

 bad black is produced for the sake of only 5 or 6 per cent, of fat. 



The author states that much more advantageous results may be obtained 

 by the employment of sulphuret of carbon. He proposes to crush the 



