March 1, 1894.] Supplement to the " Tropical Agriculturist." 
643 
the use of preservatives desirable or permis- 
sible P Many different preservatives are iu use, 
but most of them have a common foundation 
— boracic acid or a mixture of borax (biborate 
of .soda) and boracic acid. Although one may 
very rightly object to anything of the nature 
of a drug iu food, it has not been shewn that 
boracic acid when used in such proportion as 
is necessary to keep cream and milk sweet for 
a reasonable time has any harmful effect. 
.Salicylic acid was formerly in much use, but 
it canuot be too widely known that its use is 
distinctly dangerous, that it has been condemned 
by medical authorities, and its sale not allowed 
unde-r the English Pood and Drugs Act, and 
that it should on no account be used in con- 
nection with food. Boracic acid, or a mixture of 
bo.Mv nid boracic acid i.s tlierefore the safer sub- 
stance to use ; but great caution must be exercised 
especially iu dealing with milk, on account of 
the greater quantity that is consumed. It may, 
indeed, be well supposed that in the case of 
infants, whose diet is so largely composed oF 
milk, the con,sumption by them of milk to which 
preservatives have been added may be harm- 
ful. The amount of preservatives necessary for 
keeping cream or milk for a short time is very 
small. The following recipe is that of a mix- 
ture which will keep cream quite sweet for 4 
or 5 days in England, even in hot weather, 
it is said: — 1 oz. boracic acid, or j oz. borax 
and f oz. boracic acid dissolved in a quart of 
hot water. This will suffice for 20 gallons of 
milk or a table spoon of the solution to a 
quart (1 to 3,200 parts). Much stronger solu- 
tions are in constant use, as large a quantity 
as 1 oz. boracic acid being sometimes put to 2 
gallons. But when strong solutions are used, 
some other substance must be added ; for water 
will hold but a small quantity of borax or 
boracic acid in solution, and only a limited 
quantity can be put in without weakening the 
cream or milk, besides which the acid would 
give a bitter taste. Hence glycerine and gela- 
tine are .sometimes used as preservative mix- 
tures. Both will hold a large quantity of borax 
and boracic acid iu solution, and take away, 
to a certain extent, the bitter taste, though 
gelatine does so more effectually than glycerine : 
2s oz. of gelatine steeped in 2 or 3 oz. of water, 
and dissolved in a solution of 1 oz. of mixed 
borax and boracic acid in a pint of hot water 
will, wiien cool, form a jelly which will keep 
any length of time. A tea spoon of the jelly 
will, it is said, preserve a pint of cream from 
7 to 9 days iu l^nglaiul. If these mixtures are 
used they should be added very sparingly, as 
a large quantity would artificially thicken the 
cream. 
Sterilization and the use of preservatives, it 
must be rememl)ere<l, only destroy or arrest the 
lactic acid ferments, and do not affect the 
numerous otlier bacteria which go on multi- 
plying with the age of milk. It is, therefore, 
ii"i<on(il>le to suppose that milk and cream may 
not bt; wholesome even though they may not 
have turned sour. Aiul to keep milk or cream 
tor any li>iigtli of lime would appe sr uiidcf ir- 
able. We should bear in mind tluit milk and 
crettin are eveutuully perishable articles, and 
are intended for immediate cousumptiou, though 
by the careful and iimited' use of preservatives 
they may be kept for i short time without 
any deleterious effects. 
NOTES FROM THE NORTH. 
1 (Continued from paffe 59 of No. 8.) 
10. The tillage done by the Jaffna cultivator 
i^ more thorough iu its nature than that prac- 
tised by cultivators in other parts of Ceylon, 
lie plougfis aud reploughs the land over and 
over again, so that the ridges which are invari- 
ably left after the first ploughing with the 
ordinary native plough may be entirely broken 
up, aud he does not restrict his ploughing to 
the ^addy land, but he ploughs the garden land, 
aud lu fact he is said to plough all land that 
can by any possibility be ploughed — a practice 
I unknown iu the Sinhalese districts. Iu tlii^ 
case of tobacco lands, instead of the first plough- 
ing, the soil is in most cases turned over with 
I the mamotty, and in the last ploughing the 
I soil gets so loose and pulverized that the plough 
1 works without any pressure on the handle. 
I 11. The Jaffuese make up for the poverty of 
I the soil by careful manuring, making use of 
j every available scrap of manure. But the mis- 
1 take they make in common with the Sinhalese 
goiyas is to leave the heaps of cattle manure 
in the open, exposed to sun and rain — a mis- 
take that can be very easily rectified. 
The sheep is the animal largely used for 
i penning on garden lands for manure so as fo 
1 utilize both the droppings and the urine. Thi-' 
I Jaffuese generally prefer goat mutton, and they 
! have some prejudice aginst eating the mutton 
I of the sheep connecting certain skin diseases 
I aud impurities of the blood witli it : and the 
1 wool found on them is next to nothing. But 
I they are highly appreciated for the manure 
I they yield, and rich gardeners own them iiy 
; hundreds. 
; 12. The practice of applying green leaves 
to the soil is a very good one, and cannot be 
j too highly recommended for the Jaffna soil whidi 
is naturally poor iu humus. During the month 
of January we find gardeners eagerly buying uji 
leaves that grow on the hedges, trees and under- 
growth of the compounds and taking them l>v 
cartloads to their tobacco lauds. There are manv 
kinds of leaves which are very much souglit 
after by gardeners for this purpose, and there 
is no doubt that experience forms a safe guide 
to them as to which to select and which to 
reject. But there is one species of plant very 
commonly used as green manure which is deser\ - 
ing of special mention. I mean the common 
shrub called Tephrosia Tinctoria by botanist^j, 
and known as kavilai in Tamil aud pila iu 
Sinhalese. This plant stores up valuable nitro- 
genous matter which it probably takes from 
tile air. Being a leguminous crop it is also 
' rich in lime, so that it must be a very suitnbli' 
1 manure for tobacco. 
13. The alg;B or sea weeds washed adrift to 
' the shore are very commonly used iu Jaffna a.s a 
I manure forgnrdeu lands and paddy-lield.s, provided 
I they are not lM!icki.--h. *>ea weed is p«'*.Miliarly 
1 ricli in the alkalies potash and sikIh, and i» u.seii fis 
