February r, 1888.] THE TROPICAL AGRICULTURIST. 
5i7 
of rural affair*, rather than to students of chemistry. 
Free use has been made of German publications in 
agicultural chemistry, find ol the writings of Prof. B. 
,V. Johnson, of Ncwhaven, Connecticut. Some oj the 
matters treated of in his two well-known books, ft flflW 
Crops (!ro\v" and "How Crops Feed," have been 
omitted, or only lightly touched, in the present volumes, 
which are therefore, to a certain extent, a supplement 
to those books. 
The present volumes treat of the chemistry ot the 
atmosphere, of waters, of soils, and of manures, and of 
their several relations to plants; the chemistry of 
animal life and nutrition, is not dealt with. A large 
amount of valuable information, partly of historical 
interest, has been brought together; and much of it 
is presented in the somewhat old-fashioned English 
of the best writers of New Englaud. 
One illnsiration given by the author, to show that 
liquids penBtrarte iuto plants through their roots, we 
do not think very happy. He notes an observation 
made by himself, that Indian corn made to sprout 
in a flower-pot and watered with milk had white 
1; and he suggests that the minute particles of 
solid matter in themilk must have entered the plant 
and caused the whiteness. He admits, however, that 
the whiteness may have been due to chemical 
action. Iu noticing the growth of plants i= artificial 
light, he hardly gives sufficient credit to the observations 
of Siemens and of Deherain on growth in the light 
of the electric arc, both uncovered and variously 
shaded. Mr. Storer has scarcely that respect for earth- 
worms with which Darwin has imbued us, for on the 
only occasion he mentions them, ho styles them 
pernicious, on the ground that harm is done to plants 
in pots by their casts, which become slimy mud when 
watered, and thus clog the pores of the earth and 
the roots of the plants. 
In vol. i. p. 295, a 6erious mistake occurs, though 
doubtless by oversight: it is stated that nitrate of 
soda used as a top-dressing for mowing-fields that 
contain true grasses "favours the growth of clover 
rathe r than of grass." Tho reverse of this is the 
truth. There is a good chapter on irrigation, in 
which it is pointed out that, "in spito of all that 
has been done of late years in California and the 
adjacent regions, it is still probably true that no 
other subject relating to agriculture so much needs 
to ho attended to by the American people as this 
matter of watering the land." The questions of the 
disposal of excre'ta and of sewage arc dealt with ill 
their chemical aspects. Perhaps, hardly duo credit 
is given to tho latest improvements in some 
precipitation processes for clarifying sewage, but we 
are glad to see that the author fully realizes that 
tho sewage subject is essentially a sanitary and not 
an agricultural question. Me also exposes some 
economic fallacies as to the value of sewa :«s by citing 
various instances in which valuable matters are found 
at our doors so diluted as not to be worth the cost 
of collecting or saving. One illustration is the 
presence of gold in the clay of Philadelphia— 1 of 
gold in about 1} million of clay. If the gold from 
tho bricks of the houses could be brought to the 
surface in the form of gold-leaf, ou each brick would 
be a Midi D surface of 2 square inches. In the clay 
beneath the portion of the city already built ovor 
is 120 million dollars" worth of gold, yet no ouo 
dreams of extracting it. So, except under Very favour- 
able conditions for the sewage, valuable manures may 
be obtained mori! cheaply than from sewage. 
The necessity for the selection of ripe, as well as 
pure, seed* for sowing, ami especially on poor soil*, 
is insisted on and illustrated by records of experl. 
mentr. Tho great importance, whi ther for good or 
evil, of micro-organisms to the farmer, it often pointed 
out; and the writrr discusses th ■ question of the 
sources of nitrogen available for plants, and the very 
importnnt question ns to the fixation of free nitrogen 
front the air by humus or by olny soils. The conclusions 
of U'Tthidot, Armsliy, Dele rain, and others are 
itMed, and the author rrgnnU it as provi u in tho 
light of existing knowh Ige that some nitrogen from 
tho air * really fixed as an incident to curtain fer- 
mentations which occur in the soil. This much debated 
and debatable point, which is of the utmost economic 
importance, still requires further elucidation ; and we 
may hope that some further light will be thrown on 
it by the researches of Sydney Vines on the nutri- 
tion of the common bean. — Nature. 
♦ 
BUTTER- MAKING. 
Butter-making as a science is utterly unknown in 
this country, but to those who may be engaged in 
this industry on any considerable scale, the following 
instructions for butter-miking, which are observed 
at the Ontario Agricultural Collage Farm, Canada, 
will perhaps commend themselves as worthy of con- 
sideration : — 
1. Good ventilation for the milk-house, milk-cellar, 
or diary-room is most essential, and may he pro- 
vided for by leading an air-drain under ground for, 
say, 200 feet. Through it a supply of pure, fresh, 
cool air may be admitted. The foul or warm air may 
be allowed to escape through ventilators or windows 
in or near the ceiling, 
2. Cream should invariably be removed from the 
milk, before the milk is sour. 
3. The cream of each churning should be gathered 
iuto and kept in one vessel. 
4. The whole of the cream should be well stirred 
every time fresh cream is added. 
5. Iu summer, cream should not bo left louger than 
three days before churning. 
0. The best churning temperatures are between 57 
and 60 degs. during summer, and between 60 and 
G4 degs. during the winter. 
7. Butter can be more thoroughly washed free from 
butter-milk, while in the granular condition than after 
it is gathered or pressed into a roll. 
8. Only the best pure salt of medium and uniform 
fineness of grain should be used, and from three 
quarters to one ounce of salt per pound of butter 
will be found satisfactory for the summer. 
9. The utmost cleanliness in milking, in vessels, in 
utensils and in all surroundings must be observed to 
preserve the flavour aud body of milk, cream, buttor 
and cheese from contamination. 
The same authority uses the following general 
rules : — 
1. Milk from healthy cows only should be used, 
and not until at least four days after calving. 
2. Any harsh treatment that excites the cow 
lossens tho quantity aud injures the quality of her 
yield. 
3. Cows should be allowed an abundant s tpply of 
wholesome, suitable food, and as much pure water as 
they will drink. 
4. A supply of salt should bo placed where the 
cows could have access to it overy day. 
5. Cows should not be permitted to drink stagnant, 
impure water, nor to eat cleanings from horse stables, 
leeks, turnip tops, nor anything that would give the 
milk an offensive taint. 
0. All milk vessels should be thoroghly cleansed, 
first being Well washed, theu scalded with boiling 
water and afterwards sufficiently aired to keep them 
porfectly sweet. 
7. Cows should be milked with dry hands nud 
only after the udders have beeu washed or well 
brushed. 
S. Milking should be done and milk should be kept 
only where the surrounding air is pure and free from 
all. 'Objectionable and tainting odours. Milking in a 
fotiUswellidg stable or yard, Impacts In milk an in- 
paribus taint. Sour whey should never be fed, nor 
should hogs be kept in a milking yard, or near a milk 
slan I. 
9. Tin pails oulv sh mid be used. 
in. All milk should lie properly strained immedi- 
ately alter milking, aud for that purpose a detached 
strainer is preferable to a strainer \\%i\.—/n<linn Ajri- 
CllllHli/t. 
