1922.] Indian Science Congress. 1.8.C. 147 
(a) The Soe of a definite water-borne disease with an appreci- 
able mortalit 
(6) An eR record of the total Pease rate 
accurate record of the death rate due to certain individual 
diseases, both -borne and no -borne 
wa or 
e existence of a fully abr ph water ‘supply. 
S paper deals with stone xtent to which each of these factors is 
io 
e aun condition is peer satisfied by the presence of cholera in 
endemic se 
he ioe is in per Fiat Stet sufficiently accurate in many muni- 
cipalities tis meet the 
eg te. is at soslane unattainable. 
urth is also © open to serious doubt, for the term ‘‘ protecte 
as flied to wer avers. in the Madras Precae can only be re fet 
as relative and in most cases does not come se to the standard required 
for a athe application of rs phenomenon 
Limitations of B. Coli method in water examinations.— 
y Rao Saute V. GovinDaraJu. 
Contradictory oe are at present held on the subject of bac- 
terial standards of purity of water in India. My recent researches tend 
to some light on one of the causes of this divergence of opinion 
The presence of fro o o be responsible for an 
waters is apt to be misleading in the case of waters of great purity like 
mountain spring waters. Again stasis in reservoirs and passage through 
Pipes may be responsible for an increase in mr bacilli, ey that a mere 
increase in the number of faecal bacilli, in a water does not necessarily 
indicate faecal contami nation but may simply - ie to tela in reser- 
voirs or to flow through pipes. 
The Sack Steam Disinfector.—By Masor L. A. P. ANDER- 
son, I.M 
fessor 0 
An e of disinfector devised by Col. P. S. Lelean, Pro of 
Hivaiens: at td edi R.A.M. College, called the ‘* Sack Ste. am Disinfector, 
was brought to the notice of the Indian Science oe rn the cease : 
The special —— claimed for this appa ability oP goer 
@ low initial cost, simplicity of construction, portabi ae Ig 
ne price cy and sieess utility for civ 
adh of Seiatieede ae has a been elaborated into sites types 
for use pe fata arying circumstance 
The disinfector is very s ‘nla in n construction n and co: 
ly of asteam tight sack 2’ by 4}’ of heer Big feet capac 
which igs connected b hose to ge mall gaee re rs d isplacement by 
ned in the sack. The water geeks gZ pipe 
nsists essential- 
of the boiler is arranged h a way that it oe water : "ae 
the boiler pressure exc 3” water-he nigh 
steam through the pipe ees warning that the boiler requires pucseicaat 
in a very simple and yet effective Se fbr gl 
no skilled attention for its supervision cide. Ad r of 
prove efficiency of the disinfector as a germicide. lities hospitals, 
this type ould be of special value in schools, m Tabour camps, pilgrim 
and i —— especially in the mofussil, ships, !abo 
centr = 
