f06 
Supplement  to  the  “ Tropical  Agriculturist.^’ 
[Jan.  1,  189?. 
does  not  turn  at  the  proper  rate  which  is  about 
6,500  revolutions  per  minute.  To  safeguard  against 
this  error  the  friction  pulleys  shoultl  be  rubbed 
free  of  oil  immediately  before  starting  the 
machine.  The  separator  shouUl  be  set  accurately 
level  and  fixed,  so  that  it  cannot  be  dislodged 
from  its  position.  All  its  parts  must  be  kept 
Bcrupulously  clean  and  the  friction  portions  be 
regularly  oiled  with  the  purest  lubricating  oil 
obtainable.  Milk  should  be  warm  when  under- 
going separation.  The  temperature  at  which  it 
is  drawn  from  the  under  is  sufficiently  high.  If 
milk  is  colder  than  90oF.  before  it  is  brought 
to  the  dairy,  it  must  be  raised  to  at  least  that 
tamperature  before  it  is  separated.  This  is  speci- 
ally necessary  wdth  buffalo  milk  which  ordinarily 
is  extremely  rich  in  butter  fat.  A temperature 
cani.e.,atin  vessel  with  a tight  fitting  lid,  and 
containing  hot  water,  if  dipped  into  milk  and 
gently  moved  through  it,  will  soon  raise  the 
temperature  to  the  desired  standard.  All  milk 
before  separation  should  be  well  strained  first 
through  a wire  or  hair  sieve  and  then  through 
muslin,  a double-fold  of  whicii  may  be  stretched 
on  a strainer  frame  of  ordinary  form.  If  the 
quantity  of  milk  to  be  strained  is  considerable, 
both  the  wire  and  muslin  strainers  should,  from 
time  to  time,  be  rinsed  in  jture  water  as  the 
straining  proceeds.  This  should  be  done  as  often 
as  there  is  any  observable  accumulation  of 
foreign  matter  on  the  strainers. 
Complete  separation  means  that  less  than  A 
per  cent,  of  butter  fat  remains  in  the  separated 
milk.  It  may  be  stated  that  approximately  wdiole 
buffalo  milk  yields  ^ cream  and  | separated  milk, 
and  that  2 lbs.  of  the  cream  will  yield  from  1 lb. 
to  Ig  lbs.  of  butter.  A pound  of  butter  can  be 
made  from  9 lbs.  of  milk,  if  rich,  but  it  wdll  take 
16  lbs.  to  make  the  same  quantity  if  the  milk  is 
poor.  Euffalo  milk  is  so  rich  in  butter  fat  that 
the  ordinary  lactometer  as  graduated  for  use  in 
England  is  necessarily  misleading  in  India — thus 
it  will  indicate  that  separated  milk  is  of  better 
quality  than  whole  buffalo  milk.  To  make  this 
plain  it  may  be  stated 
that  the  lactometer 
will 
show  pure  milk  when  8 per  cent,  of 
been  added  to  separated  milk. 
w^ater 
has 
Slightly  salted  pure 
proximately  : — 
butter  should 
contain 
ap- 
Water 
• • • 
...  7-5 
Salt  ... 
• • 
..  PI 
Casein. . 
• • 
. . OG 
Milk-sugar 
• » 
...  0-3 
Butter  fat 
• • 
...  90-5 
Butter  can  be  made  to  take  up  water  to  the'  ex- 
tent of  nearly  20  per  cent-  The  presence  of  a 
high  percentage  of  water  indicates  that  the  butter 
has  not  been  properly  washed  ; because  the  re- 
moval of  butter-milk  and  other  impurities  from 
butter  implies  not  only  thorough  washing,  but 
thorough  working  or  squeezing  also.  The  process 
should  not  leave  more  than  10  or  12  per  cent, 
water  in  the  butter.  Imperfectly  washed  butter 
contains  butter-milk  and  curd.  The  nitrogenous 
substance,  casein,  is  highly  fermentative  and  th« 
presence  in  the  butter  of  even  a small  per- 
centage causes  the  butter  soon  to  turn  tancid. 
Eancidity  is  believed  to  bo  due  to  a Chemical 
change,  i.e.,  The  s])litting  up  of  butyrine  into 
butyric  acid  and  glycerine.  Air  and  liglit  are 
necessary  to  initiate  the  change  The  melting 
point  of  butter  is  of  some  importance.  It  is  a 
means  by  which  expert  analysis  can  detect 
whether  it  has  been  adulterated  by  animal  fat 
or  vegetable  oil.  The  food  given  to  dairy 
cattle  however,  influences  the  melting  point. 
Those  foods  which  are  least  astingent  produce 
the  softest  butter.  Cotton  seed,  pulse  meal, 
pea  straw  and  other  pulse  fodders,  also  ground- 
nut cake  produce  lirm  butter,  whilst  manj'  oil 
cakes  give  soft  greasy  butter.  A simple  and  home- 
ly method  of  detecting  impurities  in  butter  is 
to  place  a small  piece  in  a test  tube  and  plunge 
the  tube  into  hot  water.  The  butter  melts  and 
separates  into  layers  which  will  indicate  ap- 
proximately the  relative  propotions  of  its  cons- 
tituents. The  clarified  butteiYghiJ  will  form  the 
upper  layei’,  the  curd  a middle  layer  dividing 
the  ghi  from  the  w'ater  which  will  occupy  the 
bottom  of  the  test  tube. 
THE  CLASSIFICATION  OF  COTTONS. 
A late  issue  of  the  Agricultural  Ledger  Series 
deals  with  Indian  Cultivated  Cottons.  The 
account  is  written  by  Mr.  T.  II.  Middleton.  B.  Sc. 
Professor  of  Agricultuie,  Baroda  College.  In  a 
concluding  note,  the  Editor  (Dr.  George  Watt) 
takes  exception  to  some  of  Prof.  Middleton’s 
“botanical  interpretations  ” in  the  latter’s  paper 
wdiich  Dr.  Watt  readily  admits  is  “ a most  valu- 
able contribution  to  our  knowledge  of  the  cotton 
plants  of  India.”  The  Editor  thus  refers  to  the 
difficulties  in  classifying  the  various  kinds  of 
Cotton  that  are  found  under  cultivation: — 
The  subject  of  the  origin  of  the  various  races 
of  cotton  in  the  world  is  a subject  wdiich  unfortu- 
nately has  its  parallel  if  not  its  origin  iu  the 
obscurity  that  involves  the  determination  of  even 
the  species  of  Gossypuim.  While  a very  large 
proportion  of  the  cotton  area  of  India  still  remains 
to  bo  explored  by  me,  I do  not  propose  to  publish 
my  peculiar  views  of  the  botanical  jiroblems 
briefly  touched  on  by  Professor  Middleton.  I 
may  say,  however,  that  the  errors  that  obscure  the 
study  have  passed  down  from  the  very  earliest 
times,  so  that  certain  species  described  by  even 
Linmeus  himself  in  his  Species  Plantarum  will 
have  to  be  spoken  of  in  future  as  not  being  the 
species  of  that  name  in  his  herbarium.  If,  there- 
fore, uncertainly  exists  as  to  the  exact  iilants 
meant  by  Linnaeus  under  such  names,  for  ex- 
ample, ns  Gossypium  barbadense,  G.  hirsutum  aud 
even  G.  arboreum,  it  is  no  w’onder  that  numerous 
subsc(iuent  writers  have  got  hopelessly  confused 
and  new  names  such  as  G.  obtusifolium,  G.  iu- 
dicum,  G.  'Wightianum,  G,  roseum,  and  G. 
neglectum  have  been  proposed  and  rejected  or 
translated  from  one  form  to  another.  The  writer 
had  the  pleasure  recently  to  receive  a large  and 
valuable  collection  of  obtnnical  specimens  of 
Gossypium  from  the  United  States  of  America. 
These  proved  of  exceptional  interest  since  they 
revealed  the  fact  that  G.  herbaceum  of  American 
writers  was  for  the  most  part  neither  the  G. 
Herbaceum,  Li/m  Sj).  IH.  nor  G.  herbaceum,  Linn 
Herb.  The  intei'est  in  thi.s  matter  turns  mainly 
on  the  interpretation  that  must  now  be  placed  on 
th(j  so-called  American  hybrids  between  that 
