Show Spontaneous Combustion in Hay Har 1 HE creation of extensive hay dumps for T THE army requirements brought into great prominence the question which is over re current in agricultural practice as to the extent to which spontaneous t ignition may take place and the conditions that are arc favorable to it The commonest cases of spontaneous heat production are arc of course those in which living material seeds leaves etc undergo a sweating process when placed in heaps and this change which is associated with respiratory and changes also proceeds to a certain extent in stacks of green or fresh hay A much more potent effect according to a writer in Nature is however exerted by the tho growth of organisms micro-organisms bacteria and moulds some of which have been shown to be capable of 01 raising the temperature to upwards of 70 degrees C. C Beyond this temperature it is doubtful whether even these organisms can continue continuo growth and this view is supported by the tho fact I I l 4 fl f. f 1 f. f rS t i tf it t t tf f t M r S. S ft i j ji 1 i tt f that only carbon di dioxide We and not i m iii gas g as s is produced but the high temperature II al f c o ready reldy attained and possibly the wie products l- l chew chenU microbial action serve to initiate purely th th e raise eventually raw cal oxidation changes which temperature to the region of 95 90 degrees degree this the hay assumes a si clark During phase small quantities of form formic is brown or black color acid are produced and there thero is a loss Josf of o jj F constituents W sans and other nitrogen free unable to w wrise g gt of latter temperature is course the fact that ai s substances sub sub- frise f rise to firing but in in view of become on ex stances such as bran sad and P to temperatures of degrees degree es that energetic changes take place as lo low as JS degrees it has hns been assumed that o n Pro prolong jJ occurring in tb tw the 1 action at af the temperature g sta tack stack s k may y also result in the formation i of sun sim r rs wont The of mo substances presence compounds compound a ad d i nr ure e and of easily decomposable free air supply are predisposing co earth conditions excessive heating t f. t. t I 1 t t 1 1 i 1 L. L r. r O fi- fi 6 t-r- t 1 i ow t |