It often happens that a horse-owner in a foreign country, can obtain for his animals two or more grains, none of which are of suitable composition; although a combination made from them might give the desired result. For instance, we might wish (as I have done, when stationed in Eastern Assam) to combine unhusked rice (paddy) and gram, so that the mixture might contain the same percentage of nitrogenous matter as oats, which we may accept as the best grain for all ordinary requirements. To do this, we can look up the table of analyses on pages 62 and 63, and will then find the following figures.

Let x = percentage of paddy in mixture, and 100 - x = ,, ,, gram ,, ,,.

6.3 x 19.5 (100-x).

Then,----+|----------------------= 11.3.

100 100 x = 62 (about).

Therefore the required mixture should contain about 62 per cent. of paddy, and 38 per cent. of gram.

Again, suppose we wanted from maize and beans to get a mixture having 12 per cent. of nitrogenous matter, we might proceed as follows:

Let x = percentage of maize in the mixture.

10.3X 25.4 (100 - x)

------ + ---------------------- = 12

100 100 x = 88.7

Therefore the mixture would contain 1 part of beans to about 8 parts of maize.

For reasons already stated (p. 68), these calculations are only approximately correct; although their limits of error are not sufficiently great to materially affect practical results.

Maize and linseed will be the most suitable constituents for increasing the respective proportions of starch and fat in a mixture of food. Both hay and straw furnish a liberal supply of fibre and ash.