do2 
being obtained by the electrolysis of salt. This chloride of lime is cont- 
posed largely of calcium laypochlorite. When added to water this lhypo- 
chlorite dissolves, leaving a residue of calcium hydrate and calciui car- 
bonate. Both of these substances are entirely harmless factors in a bath 
water. The oxidizing power of the commercial chloride of lime is repre- 
sented by about 85 per cent of available chlorine. It is nascent oxygen 
that is the purifying factor, not the chlorine. 
The capacity of the Purdue swimming pool is 85,000 gallons, and GSO 
grams of the chloride of lime were used at each dose. This would be about 
the equivalent of 20 pounds to the million gallons. Before starting the 
experiment with the chemical, bacteriological analyses were made of the 
water for a week, the pool being emptied twice. No attempt was made to 
keep track of the number of bathers in the pool. 
The following table shows the results of the analyses for the week 
before using the chemical dosage, compared with the results of the analyses 
for the week while the dosage was going on. During the latter week, that 
is, while the tank was being dosed with the chemical, the water was not 
changed at all. 
The method of applying the chemical was to sprinkle it on the surface 
of the water in the pool. This was easily done with one trip around the 
edge, throwing the powder as one walked. The time occupied in this 
process was less than two minutes. 
No. of Bacteria 
Date. per c. c. B. Coli. 
Monday, November 1, pool just filled............... 560 None 
WVENENS 7 ETE WSO racssty cote tees) ov eheuerares br evened ieuenerstoe 6,160 Present 
Mesdayea. ms INOVEMDER Zi is co sisiete ole wus were oaelete and 20,650 Presen| 
BIVETUMNG VATECR USC. stds shoters cree ticle wake woateneenetedape 37,600 Present 
Nwednesday. a: smi, November Siva. . acters aa ays ese 27,800 Present 
WVEnING CAITR Ge: aie Ate. © chek ocgls erento. GOD00 Present 
Tank emptied. 
THUrSaay Ah. GUSt ALCL Tie: oe. cet alad ole. serene 930 None 
VEMIN es 4 ACE USC iio cs 5-5 Bin e Stn ehcteny soles eden are ae te 8.500 Present 
lriday a. m., temperature of water 85 Wahr......... 109,200 Present 
VOM SS nUer ASCs « 2is7afe test Sia,.01e ets wet tas eo obe ett octane 106,400 Present 
Say as ., ONOVEDIDER: (07.3%, cc lele ch etre eres 118,000 Present 
BIVEMUING < SUL UCT: MUISCS sw cate cose ssw See "ey aetnp a acerare, eatacaant aes 140,000 Present 
