WARNING TM    5-6630-215-12 d. Comparator, Color,   Hydrogen   Ion   and   Residual   Chlorine,   (Deter- mination  of  pH)  (fig.  2-16). (1)   pH   Values. In  determining  pH  values,  this  comparator  mea- sures  them  as  simple  numbers  conforming  to  the  hydrogen  ion  scale. The  sample  cells  have  a  26  mm  viewing  depth  and  hold  15  ml  of  samples when  filled  to  the  mark  on  the  cells. The  pH  color  disc  furnished with   the   comparator   contains   nine   permanent   values. The  reagent bottle  has  a  color  coded  (white)  label  and  cap  to  indicate  the  pH indicator    solution. The  pH  color  disc  being  used  in  the  comparator  is also  marked  to  show  the  solution  to  be  used. A  prism  eyepiece  is provided   for   accurate   comparison. Orthotolidine. Danger,   contains   acid. Can  cause severe  burns. Avoid  contact  the  skin  and  eyes. Avoid   breathing   vapors. Antidote: External, flush  with  water. If  in  eyes,  wash  for  15 minutes. Get   medical   attention. Internal  -  call physician  at  once. Do  not  induce  vomiting  or  use carbonates. Give  large  amounts  of  water  contain- ing  milk  of  magnesia. Follow  with  raw  white  of eggs  beaten  with  water. Keep  away  from  children. Wide  Range  D  pH  Indicator. Danger,   poison. May be  harmful,  fatal,    or  cause  blindness  if  swallowed. Cannot   be   made   non-poisonous. Keep   container closed. Avoid   prolonged   or   repeated   breathing   of vapor. Inflammable  keep  away  from  sparks  or  open flame. Antodote: If  swallowed,  call  a  physician immediately. First  Aid: Give  tablespoon  of  salt in  a  glass  of  warm  water  and  repeat  until  vomit fluid  is  clear. Give  two  teaspoonfuls  of  baking soda  in  a  glass  of  water. Have  patient  lie  down and  keep  warm. Cover  eyes  to  exclude  light. Keep  away  from  children. Arsenite   Solution. Danger.   Poison. May  be  fatal if  swallowed  or  absorbed  through  skin. Do not get  in  eyes,  on  skin,  or  on  clothing. Wash thoroughly   after   handling. Do  not  pipet  by mouth. Use  automatic  pipet. Antidote:    If swallowed, induce   vomiting   by   sticking   finger down  throat  or  by  giving  soapy  or  strong  salty water  to  drink. Repeat  until  vomit  is  clear. Never  give  anything  by  mouth  to  an  unconscious person. In  case  of  contact,  immediately  flush eyes  or  skin  with  plenty  of  water  for  at  least  15 minutes   while   removing   contaminated   clothing   and shoes. Wash   clothing   before   re-use. (Discard contaminated    shoes.) Keep  away  from  children. 2-62