422 Report of Experiments with different Manures 
more insoluble woody fibre — so far as it can be indicated by 
the results of the method above described. The means only, 
of the two or more determinations made on each specimen, are 
given in Table XVI. which now follows ; and it is these to 
which we shall confine attention. 
The professed object of determining the amount of woody- 
fibre in our food-stuffs, is to acquire some means of judging of 
their amount of probably indigestible and effete material. Now, 
it is suflBciently established by the researches of many able in- 
vestigators, among whom we mav mention Mulder, Harting, 
Boussingault, Millon, Peligot, Mitcherlich, Chevreul, Fremy, 
Cramer, and Payen, that the substance to which is given the 
somewhat generic term woody-fibre, comprises many modifications, 
which vary from each other, in physical characters, and in 
behaviour to solvents, according to age, and other circumstances 
of their deposition, and to the character and amount of the in- 
crusting matters, and of the injected, or foreign matters, with 
which they are associated. In fact, some of the modifications which 
yield most easily to certain chemical solvents, seem to be sepa- 
rated by almost imperceptible lines of demarcation, from the 
admittedly more digestible starchy bodies. The two series of 
bodies appear, indeed, to be mutually transformable, not only in 
the laboratory of vegetable existence, but more or less in that of 
the chemist also. How then, are we by the chemical analysis of a 
food, to determine exactly at what point of aggregation, induration, 
or protection by foreign substances, its Cellular or Woody matter 
is to be accounted as indigestible, innutritious, and effete? So 
long as the Cellular substance is in such a condition as to be 
easily acted upon by chemical solvents, or to be transformable 
within the plant, we may perhaps venture to assume, that it would 
not be wholly refractory to the digestive agencies of animals. If, 
therefoi-e, it be admitted, that the amounts of matter recorded as 
tcoody fibre in our Table, do not include the more delicate and 
changeable Cellulose of the vegetable substance examined, they 
may nevertheless, on that account, the more nearly represent the 
proportions of the respective hays, that will be necessarily indi- 
gestible and effete. In fact, although we do not at all claim that 
the results do indicate the total cellidose of the specimens examined, 
we still believe, that so far as present experience goes, results so 
obtained are the best means at command for the purpose of com- 
paring the specimens one with another, in regard to the relative 
proportion in each of the more refractory Cellular matter. And, so 
laras the substance which resists the action of solvents employed 
in the <legree above described, may be found to be really in- 
digestible and effete, a large relative proportion would in this 
point of view be objectionable. At the same time, it must be 
