76 REPORT — 1859. 



Lambeth, were found to be about half as much as the average residues yielded by high 

 and low water at Greenwich respectively. The summer averages at Lambeth cor- 

 responded very closely with the winter and spring averages at Greenwich. The per- 

 centage amount of suspended matter in the river was found to be twice as great at 

 low as at high water. At low water at Lambeth, the amount of dissolved matter, 

 mineral and organic, is greater at the sides tban in the middle, showing that the pure 

 stream-water cuts for itself a central passage through the foul stagnant water at the 

 sides. The same action, though in a much less marked degree, takes place at high 

 water. The up-cast flow, largely contaminated with sea-water, forces for itself a 

 central passage through the stagnant sides. Another point of interest was the differ- 

 ence in composition between the surface water and the deep water. During the flow, 

 the sea-water runs up underneath the river water, and although a complete mixture 

 of the two layers eventually takes place, yet a difference of composition between the 

 top and bottom layers may occasionally be recognized as high up as the Thames 

 Tunnel. The effect produced upon the quality of Thames water by a heavy rain-fall 

 was also illustrated. 



On a New Mode of Bread-making. By W. Odling, M.B., F.R.S., F.C.S. 



The vesicular character of ordinary bread results, as is well known, from the 

 development of carbonic acid gas uniformly throughout a mass of fermenting dough, 

 whereby a loose spongy texture is imparted to what would otherwise be a dense sod- 

 den lump of baked flour and water. In fermented bread the carbonic acid gas, 

 generated within the substance of the dough, is a product of the degradation of certain 

 constituents of the flour, namely the starch and sugar. In Dr. Dauglish's newly 

 invented process, the carbonic acid gas is produced independently and superadded to 

 the flour, which consequently undergoes no degradation whatever. Carbonic acid, 

 stored in an ordinary gas-holder, is pumped therefrom into a cylindrical vessel of water, 

 whereby the water becomes charged with the gas. This carbonic acid water is mixed, 

 under a pressure of 1 00 lbs. on the square inch, with the flour, and the resulting 

 dough, which becomes vesicular on the removal of the pressure, is divided into loaves, 

 and baked in a travelling oven. The advantages of the new process are : — 1st. Its 

 cleanliness. Instead of the dough being mixed with naked arms or feet, the bread, 

 from the first wetting of the flour to the completion of the baking, is not even touched 

 by any one. 2nd. Its rapidity. An hour and a half serves for the complete con- 

 version of a sack of flour into baked two-pound loaves. 3rd. Its saving of labour and 

 health. It substitutes machine labour for manual labour of a very exhausting and 

 unhealthful character. 4th. Its economy. Despite the heavy prime cost of the 

 apparatus, yet the use of carbonic acid is found to be cheaper than that of yeast. 

 Moreover the waste of the saccharine constituents of the flour, necessary in the old 

 process, is avoided in the new one. 5th. Its preventing any deterioration of the 

 flour. In making fermented bread from certain varieties of flour, the prolonged 

 action of warmth and moisture induces a change of the starchy matter of the flour into 

 dextrine, whereby the bread becomes sodden and dark-coloured. This change is 

 usually prevented" by the addition of alum ; but in operating by the new process, there 

 is no time for this change to take place, and consequently no advantage in the use of 

 alum. 6th. The character of the bread. Chemical analysis shows that the flour has 

 undergone less deterioration in bread made by the new than in that made by the 

 old process. The bread has been tried dietetically at Guy's Hospital and by many 

 London physicians, and has been very highly approved of. 



On some New Cases of Phosphorescence by Heat. 

 By Dr. T. L. Phipson, of Paris. 



Some years ago M. Schcenbein showed that metallic arsenic becomes phospho- 

 rescent when its temperature is raised to a certain degree. Lately, M. Linnemann 

 remarked that potassium and sodium were phosphorescent in the dark when freshly 

 cut. The phenomenon is doubtless owing to the rapid oxidation of these metals 

 when exposed to the air. The light emitted by sodium is greenish yellow, that of 

 potassium is of a redder tint. I have had occasion to examine sodium whilst phos- 

 phorescent ; its light is very feeble, and is only seen upon the surface freshly cut with 





