60 KANSAS ACADEMY OF SCIENCE. 
the conditions are not right, or the passage through the soil is too rapid, the 
process of change may be interrupted, and the analyst will find the well-water 
containing evidence of the fact in the amounts of ammonia present. Cracks and 
seams in the soil, such as are liable to occur in clayey matter in dry times, afford 
quick passage; and in the case that the surface soil has been polluted in any 
way, as, for instance, by the throwing out of the discharges from a typhoid pa- 
tient, such matter may suddenly make its presence in the water known by caus- 
ing disease in those who use it. Again, at times of heavy and long-continued 
rains, by the saturation of the upper layers of the soil, the requisite amount of 
oxygen for the maintenance of the nitrifying bacteria may be much lessened, 
thus destroying the proper balance between these forms and the putrefactive 
bacteria which accompany the first stages of organic change. Here, again, the 
water would show an absence of nitrates and an excess of ammonia. 
Generally speaking, the water derived from this underground flow, when fil- 
tered through an unpolluted soil, is a safe one; as safe, perhaps, as any that can 
be gathered. But there are troubles that are peculiar to this method of obtain- 
ing a supply, some of which have illustrations in our own state. The water is 
sometimes impregnated with iron in solution, which, on exposure to the air, be- 
comes precipitated and forms a very light, finely divided mass of floating parti- 
cles that are very hard to remove by any other means than filtration. The time 
required for ordinary subsidence is considerable and demands larger reservoir 
capacity than would otherwise be needed. If this iron-bearing water holds also 
imperfectly broken-down organic matter in solution, even if it be small in amount, 
under conditions when the average temperature of the water is somewhat above 
the normal, and in the presence of sufficient oxygen and the absence of light, 
there is very likely to develop, with great rapidity, an enormous growth of a 
species of bacteria called crenothrix. This microscopic plant is a simple cell en- 
closed in a gelatinous sheath, in which it secretes iron from the water. Though 
minute, it grows in large tufts and masses that are easily seen by the eye, fastened 
to the sides of a well or floating free in the water. It seems especially to attach 
itself to any woodwork, and also grows on the sides of the pipes of the distribu- 
ting system to such extent as to reduce their effective size and increase the fric- 
tion. Detached parts of these masses are carried far into the pipe lines and, pot 
finding sufficient food or oxygen, die and decompose, giving a fishy taste and odor 
to the water and making it unfit for laundry use, because of the staining effect of 
the iron that was secreted. Where water is obtained through driven wells these 
organisms cause a deposit of iron, which closes up the fine holes or slits of the 
points, making frequent renewal necessary. These little plants are not at all un- 
common, being found in some degree continuously in waters of this character. 
In some locations they seem to come and go, making only occasional trouble, 
while at some points it has been found necessary to abandon a source of supply 
because of them. The underflow of the Kansas river valley seems to be liable to. 
trouble of this cause. 
The storing of this water in tanks and reservoirs open to the light would pre- 
vent the development of this organism, but such method would probably lead to 
a development of the alge, which find an abundant food supply in the mineral- 
ized nitrogen. 
The pipe-line system is not free from a large range of both plants and animals, 
which sometimes develop in such numbers as to cause a good deal of trouble. 
There is a small animal, barely visible to the eye, that grows in colonies or 
masses to such an extent as to coat the interior of pipes to the depth of half or 
three-quarters of an inch. This reduces the sectional area of a six-inch pipe by 
