76 
VARIETIES. 
6.  That  the  disease  having  once  established  itself,  has  become  epidemic. 
7.  That  it  is  contagious,  if  not  infectious. 
8.  That  the  only  mode  of  eradicating  it  is  to  restore  the  original  consti- 
tution of  the  plant. 
9.  That  this  desirable  result  can  be  only  brought  about  by  introducing  a 
complete  alteration  in  the  mode  of  cultivation  that  is  adopted. 
10.  That  the  changes  in  question  should  consist, — 1st,  in  thoroughly  dry- 
ing the  seed  potatoes,  by  the  process  now  followed  in  some  parts  of  Ger- 
many ;  2dly,  in  steeping  them  for  a  short  time  in  a  dilute  solution  of  the 
sulphate  of  copper  (blue  vitriol  or  blue  stone,)  of  about  the  same  strength 
as  that  used  for  "  pickling'7  wheat  ;  3rdly,  in  planting  them  in  poor,  well- 
drained  land  ;  4thly,  and  lastly,  in  substituting  for  the  farm-yard  manure, 
&c,  now  employed,  some  inorganic  compost  similar  to  those  before  al- 
luded to. 
In  conclusion,  I  would  suggest  that  the  following  simple  experiment 
should  be  tried  in  storing  the  potato  crop  during  the  present  season  : — Let 
the  tubers  be  stored  in  the  usual  way,  but  in  the  centre  of  each  heap  or 
sackful,  let  there  be  placed  a  quantity  of  unslaked  lime,  not  in  actual  contact 
with  the  roots,  but  enclosed  in  some  porous  vessel — an  old  wicker  basket, 
for  instance — and  covered  over  with,  and  surrounded  by,  a  thick  layer  of 
straw  or  hay.  By  this  means  the  tubers  will  be  kept  dry ;  and  as  the  presence 
of  humidity  in  the  air  is  a  great  incentive  to  putrefactive  decomposition, 
one  of  the  main  causes  of  decay  will  be  removed.  The  lime,  so  soon  as  it 
has  become  slaked,  may  be  taken  away  and  employed  as  manure ;  and,  if 
practicable,  should  be  replaced  with  fresh  lime.  The  experiment  I  have 
described,  it  must  be  remembered,  can  be  easily  tried,  and  would  cost  but 
little  even  if  carried  out  on  a  large  scale  ;  it  cannot  be  productive  of  any 
injurious  consequences,  and  will  be  doubtless  attended  with  beneficial  re- 
sults. I  remain,  Sir,  your  obedient  Servant, 
Bristol,  England.  Thornton  J.  Herapath. 
On  the  Employment  of  Pentasulphide  of  Calcium  as  a  Means  of  preventing 
and  destroying  the  Oidium  Tuckeri,  or  Grape  Disease.  By  Astley  Paston 
Price,  Ph.D.,  F.  C.  S.,  Chemical  Assistant  in  the  Laboratory  of  the  Govern- 
ment School  of  Mines. — Of  those  substances  which  have  been  employed  to 
arrest  the  devastating  effects  of  this  disease,  none  appear  to  have  been  so  pre- 
eminently successful  as  sulphur,  whether  employed  as  powdered  or  flowers 
of  sulphur,  or  by  sublimation  in  houses  so  affected.  But  notwithstanding 
the  several  methods  described  for  its  application  to  the  vines,  I  am  not 
aware  that  any  has,  or  had,  appeared  prior  to  1851,  when  these  experiments 
were  instituted,  by  which  sulphur  might  be  uniformly  distributed  over, 
and  become  to  a  certain  extent  firmly  attached  to  the  vines. 
Three  houses,  situated  at  Margate  in  Kent,  in  the  vicinity  of  the  one  in 
which  the  disease  first  made  its  appearance  in  England,  having  been  for 
five  consecutive  years  infected  with  the  disease,  and  notwithstanding  the 
