58 CHAPTER 5. 



mentioned special knowledge, we shall endeavour to point out some dis- 

 tinctions, by which in most cases, though perhaps not positively, new and 

 old hay can be distinguished. 



Two great difficulties are met with at the outset. Changes are very 

 rapidly produced in new hay by heating or fermentation, which cause it 

 to simulate in almost every respect the appearance of old hay ; and 

 secondly, well-saved old hay, which happens not to have heated at all, 

 very closely resembles new hay. 



New hay, apart from any change which may be produced in it by 

 heating, is marked by green colour, by the perfect freshness of its 

 perfume, by the sappiness of its fibres, by the preservation of the natural 

 colour of its flowers, and by the absence of consolidation. If, however, 

 no fermentation takes place in the stack, the green colour of the grass, 

 the freshness, though not the perfect freshness, of its perfume, and the 

 natural colour of its flowers, may remain for almost any length of time. 

 The sappiness of its fibres, however, will gradually and sensibly diminish 

 as the year draws on. In some seasons the outside of the fibres may be 

 quite dry in perfectly new hay ; but if the outer coat be peeled off, the 

 inner stem will be found to ,be sappy. In old hay the inside of the fibre 

 will be as dry or nearly as dry as the outside. Sap is retained longest at 

 the knots. Hence in cases of doubt the fibre should always be examined 

 at the knots. If the inside of the knot is dry, it affords some proof that 

 the hay is old. 



Old hay is usually marked, by loss of green colour, by absence of fresh 

 perfume, by dryness of its fibres, by loss of colour of its flowers, fre- 

 quently by greater consolidation, especially towards the centre of the 

 stack, and in some cases by a musty smell. The outer trusses, however, 

 often retain almost all the peculiarities of new hay. Hence it is much 

 more difficult to give an opinion about one truss than about a load. 



All the above-mentioned peculiarities of old hay may, however, be 

 found in new hay, when it has been in stack for a couple of months or 

 even less, and has heated. For instance, the green colour of its grasses 

 may be lost by a few days' fermentation, and so likewise the colour of 

 its flowers. The perfume will also change from that of a new-mown 

 grass to the smell (in extreme case) of mow-burnt hay. Again, consolida- 

 tion is due to heating, not to the gradual effect of weight and time, as is 

 often supposed. New hay immediately after fermentation will be nearly 

 as much consolidated as it will ever be; whilst a stack, which does not 

 ferment, will scarcely have sunk at all at the end of a couple of years. 



Fermentation or heating, we must remark, though a farmer would 

 probably smile at so simple a remark, is not a process continually going 

 on or even going on for any considerable length of time in a stack. 

 Owing to the state of the grasses, aided perhaps by the state of the 

 weather and other circumstances, fermentation takes place, runs its 

 course, and then ceases. If it exists to any great degree, or if it lasts 

 for any considerable length of time, the chances are that the stack catches 

 fire. Stacks of hay do not heat evenly or equally all over. The heating 

 generally commences in the centre, and runs to one side or the other 



