TRANSACTIONS OF THE SECTIONS. 73 



effervescence. Altliougli he had had long- experience of the collection and analysis 

 of such water, he had not seen any thing at all to support this view. While ad- 

 mitting that the pressure was suthcient to retain the excess of gas in solution if it 

 were there, the author was unahle to see where was the source of the supposed 

 excess, since there was reason to believe that every drop of water in the ocean 

 came to the surfiice at one time or another ; and when there, it became saturated, 

 or nearly so, with gas at the ordinary atmospheric pressure. 



In the discussion which followed, the justice of the view here put forth about 

 the supposed excess of gases in solution at great depths was generally admitted. 

 Several other methods of collecting samples of the water were suggested, and also 

 apparatus for their analysis; but none of them had been tried on board ship at any 

 distance from land. 



On a 2:>r02yosed Method of iireventincj the Fennentation of Seicar/e. 

 Bif ^Y. J. Cooper. 



Ignition of Cotton hy Saturation with Fatty Oils, 

 By John Galletly. 



The fallowing experiments have been made with the view of giving greater 

 precision to our knowledge of the kindling of cotton or other exposed combustible 

 materials which happen to have imbibed animal or vegetable fatty oils. Graham 

 mentions* that "instances could be given of olive-oil igniting upon sawdust, of 

 greasy rags from butter, heaped together, taking fire within a period of twenty-four 

 hours." The danger of fire from this cause is familiar to those manufacturers who 

 coat any textile fabric with varnishes containiiig drying oils, and also to turkey-red 

 dyers, from the olive-oil employed in their process. Generally, it is stated in 

 AVatts's Dictionary that this combustion " may take place in intervals varjdng from 

 a few hours to several weeks, when considerable masses of lampblack, tow, linen, 

 paper, cotton, calico, woollen stulis, ships' cables, woodashes, ochre, &c. are slightly 

 soaked in oil, and packed in such a manner that the air has moderate access to 

 them" ( VVatts's Diet. vol. ii. p. 880 ). Nevertheless there is great vagueness about the 

 exact conditions in which actual ignition of the mass would take place, what size 

 of a heap might be necessary, and the various powers of different oils to produce this 

 result. Graham states, in the 'Ileport' already quoted, that the ignition of heaps 

 of the materials under discussion " has been often observed to be greatly favoured 

 by a slight warmth, such as the heat of the sun." This is a very important ob- 

 servation. The author's first experiments were made at a temperature of about 

 170^ Fahr., but he had some made at a heat a little over 130°, or about the tem- 

 perature a body acquires by Ij'ing perpendicular to the sun's rays ; the former tem- 

 perature might represent ithe heat attained in the neighbourhood of a steam-pipe 

 or in front of an open tire. For completeness, the author repeated, in this paper, 

 along with later results, some observations published a few weeks ago in the ' Oil- 

 Trade Journal.' 



Boiled Linseed-oil with Chamhei- lie.pt about 170° Fahr. — A handful of cotton 

 waste, after being soaked in boiled linsecd-oil, and removing the excess of this by 

 wringing, was placed among dry waste in a box 17 in. long by 7 in. square in the 

 ends. Through a hole in the cover of this box a thermometer was passed, with 

 its bulb resting amongst the oily cotton. Shortly after reaching the temperature 

 of the warm chamber, the mercurj' began to rise rapidly, viz. from 5° to 10° every 

 few minutes ; and in 75 minutes from the time the box was placed in the chamber, 

 the heat indicated was 3oO^ Fahr. At this point smoke issuing from the box re- 

 A'ealed that the cotton was now in a state of active combustion, and on removing 

 it to the free access of air it burst into tiame. In another similar experiment the 

 temperature rose more slowly, but reached 280° Fahr. in lOo minutes, when, from 

 the appearance of smoke, it was plain that the cotton was burning, and the whole 

 mass was soon in a flame on being placed in a current of air. On a smaller scale a 



* "Report on the Fire in the ' Amazon,' " Chem. Soc. Quart. Journ. vol, v. p. 34. 



