170 
Spread  of  Tuberculosis. 
Am.  Jour.  Pharm 
April.  1902. 
transmitted  by  man  to  domestic  animals  ;  while  infected  animals  in 
turn  infect  other  animals  with  which  they  are  brought  in  contact. 
Man  is  probably  rarely  infected  by  animals,  except  through  the  use 
of  milk  and  meats. 
A  series  of  investigations  made  upon  fifty  inmates  of  the  Phila- 
delphia Hospital,  all  of  whom  were  suffering  from  tuberculosis  of 
either  the  lungs  or  throat,  showed  that  such  persons  emitted  a  fine 
microscopic  spray,  in  the  acts  of  coughing,  sneezing,  talking,  laugh- 
ing and  clearing  of  their  throats;  and  such  spray,  when  collected 
for  microscopic  study,  was  found  to  contain  tubercle  bacilli  in  75 
per  cent,  of  the  cases.  Sprays  collected  during  coughing  always 
contained  many  bacilli. 
Method  of  Collecting  Sptay. — This  was  accomplished  by  means  of 
a  mask  which  was  made  from  German  silver  wire,  one  piece  of 
which  is  molded  to  fit  the  face,  resting  on  the  nose,  cheeks  and 
chin.  To  obviate  any  irritation  to  the  patient,  this  portion  was 
covered  by  a  piece  of  rubber  tubing.  Suspended  from  this  wire  is 
a  second  oblong  portion  provided  with  two  lateral  grooves,  which 
serve  to  accommodate  two  microscope  slides.  When  the  mask  is 
in  position  the  slides  are  held  directly  in  front  of  the  mouth  and 
nose,  at  a  point  3  inches  distant  from  the  lips.  The  mask  is  held 
in  position  by  an  elastic  band  which  passes  above  the  ears  and  over 
the  occiput. 
Patients  were  allowed  to  wear  the  mask  with  the  clean  slides  in 
position  for  from  one  to  one  and  one-half  hours  during  the 
day  when  they  are  apt  to  cough  least,  and  were  instructed  to 
remove  it  during  a  paroxysm  of  coughing.  It  was  never  worn  dur- 
ing the  morning  or  evening ;  the  object  being  not  to  collect  on  the 
slide  the  spray  produced  by  vigorous  coughing,  but  to  determine 
whether  or  not  consumptives  always  emitted  a  fine  spray  that  was 
in  any  way  dangerous  to  the  health  of  their  associates. 
Microscopic  Study. — Specimens  were  fixed  and  stained  by  carbol- 
fuchsin  and  Gabbett's  acid  blue  solution.  Of  the  specimens  col- 
lected from  fifty  patients,  those  from  forty-nine  were  found  to  con- 
tain bacteria,  the  diplococcus  and  the  streptococcus  being  the  most 
constant;  yet  bacilli  and  clusters  of  cocci  were  not  unusual.  A 
single  minute  droplet  often  contained  organisms  of  each  class. 
Of  these  fifty  specimens,  thirty-eight  were  found  to  contain  tuber- 
cle bacilli  in  variable  numbers,  four  to  six  bacilli  being  the  smallest 
