78 REPORT— 1869. 



and 12 per cent, carbonate. This process, then, presents the following advan- 

 tages : — 



1. Total freedom from all odour, even in an invalid's bedroom. 



2. Certain prevention of infectious diseases arising from sewer-leakage into 

 wells, or sewer-gases into houses. 



3 Enormous saving in water, and in cost of closets. 



4. It confines the nuisance instead of distributing it. 1 cwt. of charcoal per 

 month is sufficient for each closet when used by six persons daily, and the whole 

 may be allowed to fall at ouce from the closet through a 12-inch pipe to a cesspit 

 below the house, and emptied once a year. The quantity is not more than the 

 house ashes. 



5. By this process alone can the whole of the valuable material be recovered for 

 the use of the laud. Instead of forcing on the farmer a large quantity of sewage 

 when he does not want it, it enables us to store up the manure in a convenient 

 form until he requires it, and can pay its full value. 



On a remarhahle Structural Appearance m Phosphorus*. 

 By Chaeles Tomlinson, F.E.S., F.C.S. 



On the Supposed Action of Lir/ht on Co7nbustion. 

 By Charles Tojilinson, F.E.S., F.C.S. 



There is a popular idea that " light puts out the fire," and accurate experiments 

 on this point seem to be wanting ; but it is difficult to get rid of disturbing causes, 

 as every one engaged in photoraetrical observations is aware. In comparing 

 candles of the same make, the light is affected botli in quantity and economy by a 

 number of small circumstances, such as the warmth of the room, the existence of 

 slight currents of air, the extent to which the wick curls over when burning, and 

 so on. In testing the quality of gas, the standard candle defined by Act of Par- 

 liament is a sperm candle of six to the pound burning at the rate of 120 grains per 

 hour. From such a standard we get the terms " 12-caudle gas," " 14-caudle gas," 

 &c. Mr. Sugg, in his ' Gas Manipulation,' has pointed out some of the difficulties 

 in obtaining a uniform standard candle. The wick does not always contain the 

 same number of strands ; they are not all twisted to the same degree of hard- 

 ness ; the so-called sperm may vaiy in composition, one candle containing a little 

 more wax than another, or va-iable quantities of stearine, or of paraffine; the 

 candle maj' have been kept in store a long or a short time ; the temperature of the 

 store-room may liave varied considerablj', and the temperature of the room in 

 which it was burnt may have beeu high or low. All these circumstances affect 

 the rate of combustion and the illumiuating-power of caudles irrespective of the 

 action of light, if such action really exist. 



The author had a good opportunity of testing this action at the works of Price's 

 Patent Candle Company at Battersea. Under the direction of Mr. Hatcher, the 

 chemist of the Company, care is taken to ensure identity of composition and illu- 

 miuating-power in candles of the same name. There has lately been an extensive 

 series of experiments on the photometrical value of sperm caudles, during which, 

 at the request of the author, Mr. Hatcher noted the rate of combustion of such 

 candles in a darkened room, and also in broad daylight and even in sunshine. 



In the first observation, three hard and three soft candles were burned each for 

 four hours in a dark closet. A similar set of candles taken from one and the same 

 filling were burned during the same time in open daylight, partly in sunlight. The 

 average consumption per hour of each candle was as follows : — 



Sperm in the dark 134 grains. 



Sperm in light 141 „ 



No. 2 composites in the dark 133 „ 



Composites in the light 140 „ 



The temperature in the light was 72°, and in the dark 71°. There was also in 



* 



Published ia the Philosophical Magazine, Sept. 1869. 



