248 -Timehri. 
4. A microscopical examination of the centrifugalised deposit. 
5. A careful note of the weather conditions at time of collection 
especially with regard to recent heavy rains. 
The population on sugar estates (500—5,000 people) is usually sup- 
plied by water in an open trench of varying length usually from 50 to 
100 yards long and 12 to twenty feet broad and 3 to 4 feet deep. The 
water is rain water which has collected on savannahs aback of the estates 
and become deeply impregnated with peaty materials. This is allowed 
to flow many miles down the canals of the estate, which are purged of 
the previous water. The towing water is then considered pure and 
passed into the drinking trench and dammed off. This procedure is 
repeated at intervals of 3 to 4 months according as need arises. A few 
estates conserve rain water in direct trenches alongside the dwellings. 
One or two estates collect rain water in large concrete reseryoirs. 
These shallow trenches, often alongside the public road, are in many cases 
unfenced and unprotected in any way. Heavy rain quickly washes all 
sorts of pollution into these trenches, and it is no uncommon thing to 
see pigs, goats, cows and other animals walking in these trenches 
undisturbed. In some cases, houses and coolie ranges have been built 
on the banks, within a few feet of the drinking water supplies ; in con- 
sequence, all kinds of household and animal refuse can be seen upon 
these banks, which frequently slope from the dwellings towards the water. 
This enquiry into the hygienic suitability of these water supplies 
comprised a survey of 24 difterent estates. On all twenty-four bacterio- 
logical analyses were made, for which purpose sixty-seven samples were 
taken, some estates having three or four different supply trenches and 
in some instances 4 or 5 samples were taken of the same supply at 
different times of the year and during different seasons. On eleven of 
these estates the supply was examined chemically, twenty-nine samples 
being taken for this purpose. For these analyses sterilized chemically 
clean, glass-stoppered bottles were employed. The sample was collected 
from 6 inches below the surface of the water. The stopper was then re- 
placed, tied over with sterilized wool and canvas, and finally packed in ice. 
The bacteriological and chemical analyses are tabulated below, the 
details of the examination being omitted since they may possibly con- 
fuse. 
TABULATED RESULTS OF BACTERIOLOGICAL ANALYSES. 
TOTAL ORGANISMS. FAECAL ORGANISMS. 
| ul aae'| Wael | | 10 100 | Total 
Below | 1,000 | Above | Not Speci- Absent | 1 to a to to Speci- 
1,000 to 5,000 | 4 mens pA i | 100 1,000 | mens 
Done. |exam’d.| 1° | Perce: | perce. | perce. jexam’d. 
perce. | 5,000 
—_- — 
per ce, 
Ta 8 3 | 67 10 Si oe 12 67 
| | 
