THE  TROPICAL  AGRICULTURIST. 
[Jan.  2,  1893. 
482 
not  at  this  moment  half-a-dozen  kinds  of  essential 
oils  produced  outside  Europe  which  leave  a fair 
profit  to  their  growers  is  but  to  record  a fact  notorious 
in  the  trade.  Whether  it  be  eucalyptus,  patchouly, 
lemongrass,  citronella,  or  what  not,  a new  grower 
need  but  attempt  to  find  a sale  for  his  goods  in  Europe 
or  America  to  receive  proof  of  the  hopelessness  of 
his  task.  Saffron  is  next  suggested  as  a possible 
Cape  growth,  the  reason  given  for  advocating  it 
being  that  the  western  parts  of  Cape  Colony  are 
pre-eminently  the  country  for  bulbous  plants.  W e are 
afraid  that  here,  again,  cultivators  would  fail  to  find 
a profitable  market.  Spain  and  France  produce  saf- 
fron enough  for  the  world’s  requirements;  in  fact, 
if  rumour  speaks  truly,  the  Spaniards  are  likely  to 
restrict  their  cultivation  greatly  next  year.  Some 
years  ago  samples  of  saffron  of  very  good  quality 
from  Ceylon  were  shown  in  London,  but  the  would- 
be  shipper,  upon  closer  investigation  of  the  market 
prospects,  refrained  from  sending  any  further  con- 
signments. Scammony  and  castor  oil,  which  are  also 
suggested,  are  similarly  likely  to  cause  disappoint- 
ment, though  it  is  but  fair  to  say  that  of  the  latter 
drug  South  Africa  now  imports  large  quantities  from 
India,  in  spite  of  the  abundance  of  the  licinus  plant 
on  her  own  soil.  But  is  there,  then,  no  consolation 
anywhere  for  the  intelligent  and  industrious  cultivator, 
anxious  to  lead  the  way  in  new  methods  of  culti- 
vation ? There  is ; and  such  a one  need  not  go  far 
a-field.  The  choicest  gifts,  as  the  poet  has  said,  lie 
neglected  around  him — lie  close  about  his  feet.  How 
is  it  that  we  get  little  beeswax  and  practically  no 
honey  from  the  Cape  ? To  Professor  MacOwan  the 
same  question  has  evidently  occurred  and  he  can 
only  answer  that  the  almost  entire  absence  of  both 
products  from  among  the  list  of  Cape  exports  is 
inexplicable  to  him.  So  it  is  to  us.  We  import 
thousands  upon  thousands  of  packages  of  honey  from 
Chili,  California,  Jamaica,  Cuba,  Australia,  and  other 
countries  every  year,  and  hundreds  of  tons  of  bees- 
wax from  almost  every  part  of  the  world.  Both 
honey  and  beeswax  are  products  of  which  the  con- 
sumrtion  is  increasing  materially.  Neither  in  Cali- 
fornia nor  in  Chili  is  bee-farming  as  yet  a generation 
old.  Fine  pressed  honey  in  tins  is  worth  about  45 3. 
per  cwt.  now  upon  our  markets  ; good  yellow  Jamaica 
beeswax  from  ll.  5 s.  to  11.  15s.  per  cwt.  But  if  the 
Cape  people  must  needs  introduce  some  new  eco- 
nomical plants,  we  should  think  that  the  cultivation 
of  insect-flowers  offers  about  as  good  a prospect  of 
success  as  that  of  any  other  drug.  By  providing  a 
cheap  and  plentiful  supply  of  insect-powder  the 
cultivator  would  not  only  benefit  himself  financially, 
but  he  would  have  the  satisfaction  of  contributing 
largely  to  the  comfort  of  his  fellow-citizens  all  over 
South  Africa.  The  commercial  cultivation  of  the 
plant,  we  believe,  is  about  to  be  undertaken  now  in 
Natal,  and  the  growers  there  commence  with  the 
prospect  of  a practically  unlimited  market  at  their 
own  doors. 
Professor  MacOwan,  in  his  evidence  before  the 
Commission,  comments  severely  upon  the  slovenly 
manner  in  which  aloes-juice  is  prepared  m South 
Africa.  With  a proper  mode  of  cultivation,  he  thinks, 
Cape  aloes  might  be  made  as  valuable  as  the  best 
Socotrine  kind,  which  now,  we  may  observe  by  the 
way,  fetches  about  six  times  as  much  money.  ±he 
Professor  mentions  the  interesting  fact  that  m I860 
an  English  farmer  in  Natal  showed  him  a calabash 
of  treacly  aloes-juice,  which  he  had  prepared  experi- 
mental^ for  the  English  market,  and  which  contained 
as  large  a proportion  of  crystallisable  aloin  as  the 
best  Socotrine  aloes.  Unfortunately,  the  experiment 
was  not  repeated.  The  reason  that  the  Cape  aloes 
of  commerce  contains  no  aloin  must  be  sought, 
Professor  MacOwan  thinks,  solely  in  the  unwork- 
manlike manner  of  its  preparation.  If  this  view  be 
correct,  we  shall  have  to  revise  our  authorities  -Natal 
aloes  is,  indeed,  known  to  yield  an  aloin  (‘‘Natalom  ), 
but  all  pharmacognosists  have  hitherto  held  that  in 
Cape  aloes,  which  is  the  produce  of  a different  plant, 
aloin  is  constitutionally  absent. 
Of  the  other  drugs,  the  cultivation  of  which  Pro 
feasor  MacOwan  discusses,  jalap  would  seem  to  us 
to  offer  a fair  chance  of  remunerative  cultivation ; 
and  if  the  South  African  farmers  could  be  induced 
to  see  the  wisdom  of  investments  for  the  future,  it 
might  be  advisable  to  try  the  cultivation  of  camphor, 
which  has  been  successfully  accomplished  in  Florida 
and  in  certain  parts  of  Natal.  In  fact,  the  planting 
of  forest-trees  is  usually  a profitable  investment; 
“but,"  says  our  witness.  “I  doubt  if  patience  is  a 
common  virtue  here.  In  this  colony  we  plant  trees, 
truly,  but  they  must  be  quick-growing  ones  or  we 
will  have  nothing  to  do  with  them.  Then  we  cut 
them  down  for  timber  while  they  are  still  babes, 
and  cry  out  on  them  for  not  having  heart-wood." 
After  all,  perhaps,  nothing  among  new  cultures 
will  pay  the  South  African  soil-tiller  better  than 
the  intelligent  cultivation  and  treatment  of  edible 
fruits  of  all  kinds,  and,  in  some  parts  of  his  country, 
of  fibre-plants.  For  these  he  has  the  materials  ready 
at  hand.  He  might  raise  bad  exotic  drugs  which 
would  compel  us  to  throw  hie  physic  to  the  dogs, 
much  as,  in  the  Transvaal,  he  throws  his  own  peaches 
to  the  pigs. — Chemist  and  Druggist. 
INSECTICIDES. 
BY  HOWABD  EVART3  WEED. 
The  term  fungicides  is  used  to  designate  those 
substances  which  kill  low  vegetable  organisms 
known  as  fungi,  and  in  like  manner,  substances 
which  are  u ed  to  kill  insects  are  known  as  in- 
secticides. Fungicides,  as  a rule,  consist  of  com- 
pounds of  poisonous  chemical  substances,  while  in- 
secticides may  consist  of  similar  combi  - ations,  as 
in  Paris  green,  or  simply  powdered  plants,  as  in 
pyrethrum.  Some  substances  may  act  both  as 
'fungicides  and  insecticides,  and  in  some  cases  we 
may  combine  an  insecticide  with  a fungicide,  so 
as  to  be  able  to  kill  plant  diseases  at  the  same  time  we 
kill  injurious  insects — thus  killing  two  birds  with 
but  a single  stone. 
Insecticides  may  be  divided  into  two  general 
classes:  (1)  those  which  kill  by  external 
contact,  and  (2)  those  which  kill  by  internal 
contact.  The  external  contact  class  are  applied 
directly  to  the  insects,  killing  them  either  by  closing 
the  breathing  pores,  as  is  the  case  with  pyrethrum, 
or  by  producing  an  irritation  of  the  skin,  as  is  the 
case  with  kerosene.  The  internal  contact  class 
kill  by  being  eaten,  and  are  applied  upon  the 
plants  being  destroyed  by  leaf-eating  insects. 
Insects  destroy  plants  in  two  ways:  (1)  by 
sucking  the  juices,  and  (2)  by  eating  the  leaves, 
according  as  to  whether  their  mouth  parts  are 
formed  for  sucking  or  for  biting.  Insects  which 
suck  the  juices  from  plants  have  the  various  parts 
which  form  the  mouth  prolonged  into  a beak, 
and  are  known  as  Haustelate  Disects.  Those  insects 
which  eat  the  leaves  of  plants  are  provided  with 
more  or  less  well-developed  mandibles  or  jaws  by 
which  small  particles  of  the  leaves  are  eaten  off 
and  taken  into  the  stomach.  These  are  known  as 
Mandibulate  Disects. 
The  external  contact  class  of  insecticides  are 
applied  to  the  haustelate  insects,  and  the  internal 
contact  class  to  the  mandibulate  insects.  Sometimes, 
however,  it  may  be  convenient  to  apply  the  external 
contact  class  to  the  mandibulate  insects;  but  the 
internal  contact  class  are  never  used  for  the 
haustelate  insects.  Thus  we  may  apply  Paris  green 
to  any  true  bug  and  it  will  have  no  effect. 
Pyrethrum  is  a substance  made  by  powdering  the 
leaves  and  flowers  of  the  pyrethrum  plant.  This 
plant  grows  in  tropical  and  semi-tropical  climates, 
and  is  especially  cultivated  in  California  and  Persia. 
The  pyrethrum  grown  in  California  is  known  as 
“Bubach,"  while  that  grown  in  Persia  is  sold  under 
the  name  of  “Persian  insect  Powder,"  or  “Delmation 
Insect  Powder."  Although  made  from  the  same 
plant,  the  Califor-  ia  product,  “ Bubach,”  is  much 
stronger  in  its  action,  owing,  no  doubt,  to  the  fact  that 
1 the  Persian  product  is  probably  diluted  to  make  it 
