Chemistry. S67 



The cause of these phenomena is by no means apparent. It does not de- 

 pend on a higher degree of oxidation, for the change ensues in close ves- 

 sels equally as by exposure to the air. Perhaps, says Berzelius, there may 

 be some peculiar compound of water and the acid, which is not formed at 

 the moment of solution, and which has not the property of precipitating 

 albumen. — Annates de Chimie et de Physique^ xxxv. 110. 



Remark on the preceding notice by Dr Turner. — On comparing the 

 facts observed by Berzelius and Dr Engelhart, with the formation of the 

 pyrophosphate of soda, described by Mr Clark in the 14th number of this 

 Journal, it appeared probable that phosphoric acid heated to redness may 

 be converted into pyrophesphoric acid, or undergo that change which en- 

 ables it to form a white salt with silver. To put this supposition to the 

 test of experiment, some fragments of phosphorus were treated in a plati- 

 num crucible by nitric acid, and the product heated to redness. The so- 

 lution of the resulting pure phosphoric acid precipitated a dilute solu- 

 tion of albumen ; but when carefully neutralized by carbonate of soda, and 

 then mixed with a solution of the nitrate of silver, the common yellow 

 phosphate subsided. Consequently, it was not in the state of pyrophos- 

 phoric acid. 



16. On the MdHhJhchh df BrbMne. — M. Balard, to whom we are in- 

 debted for the disfcovery of bromine, and for the knowledge of its most re- 

 markable properties, has established a manufacture of that substance for sale. 

 In consequence of the improvements which he has introduced into his pro- 

 cess, he is able to sell bromine at the following prices : 4 francs the drachm, 

 14 francs the half ounce, 23 francs an ounce. — An. de Ch. et de Ph. xxxv. 111. 



17. Researches on the Fermentation of Curd and on the Caseous Oxide 

 and Caseic Acid. By M. Henri Braconnot. — Of the curd of skim-milk, 

 spontaneously coagulated, 750 grammes were mixed with about two pints 

 of water, and exposed in an open vessel for the space of a month to a tem- 

 perature varying from 20° to 25°C. The putrefaction having fully attained 

 its height at the end of that time, the process was discontinued ; and M. 

 Braconnot states, that all the products of spontaneous decomposition are 

 obtained in this manner as completely as by waiting for a much longer pe- 

 riod. The whole products were put into a filter of linen, through which 

 passed a liquid very slightly coloured, which reddened litmus paper, gave 

 no indication of the presence of sulphuretted hydrogen or carbonate of am- 

 monia, but contained an appreciable quantity of acetate of ammonia. This 

 liquid, on being concentrated by evaporation, yielded a product of a very 

 fetid odour, owing apparently to the presence of an oily substance. To- 

 wards the close of the evaporation vapours of acetic acid passed over, and 

 a liquid of the consistence of syrup remained, which concreted on cooling 

 into a granulated reddish mass like honey, and of a saline bitter taste. 

 Treated by alcohol of 37°, it was separated into parts, the one soluble and 

 the other insoluble. The former was erroneously regarded by Proust as 

 the caseate of ammonia, and to the latter he has, with equal impropriety, 

 applied the name of caseous oxide. 



