SECRETARY'S REPORT. 67 



much changed. As long as kept in the mow in a dry condi- 

 tion, hay is not disposed to undergo any change, but l)y its 

 division, and the accession of heat and moisture, the sohition of 

 parts of its substance, and especially, by the addition to it of the 

 aforementioned excretory substances during its passage through 

 the animal, it is prone to decay. It passes through tlie stages 

 of decay rapidly, as compared with undigested hay, even when 

 the conditions of moisture and warmth are supplied out of the 

 body. 



This vegetable fibre which makes up the principal bulk of 

 the manure, in its subsequent decay, assumes a form in which 

 it is called mould, humus or geine, each name being often used 

 indiscriminately to designate it. In this condition it is an 

 exceedingly complex substance, being made up of a number of 

 different bodies, possessing varying properties. Some of them 

 are acids, showing a strong affinity for bases, and by their union 

 with these bases forming salts, having varying degrees of 

 solubility. Whether it is in this form that they are taken up, 

 dissolved in the sap of plants, or whether they go tlirough a 

 further decomposition in the soil and become carbonates of the 

 same bases, or whether the ultimate spongiole has the power to 

 eff'ect a transformation at the moment of absorption, are questions 

 not as yet determined ^ but the great fact to be remembered is, 

 that vegetable fibre, during its decay, forms humus, and by 

 means of the presence of this humus in the soil, plants are 

 enabled to exist and increase their substance. It should not be 

 inferred from this statement that humus, composed of woody 

 fibre alone, is capable of completely nourishing a plant. Pure 

 woody fibre contains simply the elements of woody fibre, and 

 not those of other constituents of the plant. Nor does woody 

 fibre derived from the pine furnish all the elements found in 

 the composition of that of the oak. The ultimate constituents 

 of woody fibre are the same in all cases, being carbon, hydrogen, 

 and oxygen ; but there are other substances found in intimate 

 relation and combination therewith, and especially the inorganic 

 matters left in the ash when the fibre is burned. 



A manure cannot give to a plant that which it does not in 

 itself possess. One composed exclusively of carbon, hydrogen 

 and oxygen, in the form of humus, cannot furnish of itself 

 complete nourishment to a plant having a composition containing 



