50 
THE YOUNG SCIENTIST. 
was greatly pleased, and told me the dif- 
ferent names of the fish, and that "you 
don't have to change the water because 
the plants keep it pure." 
I wrote it down, I repeated it to myself, 
it was constantly in my mind, " You don't 
have to change the water, because the 
plants keep it pure." Here was a new 
revelation in plant life, and I thought to 
myself what very pure water must be con- 
tained in water-cress beds. 
I was sure this plant must be foreign 
and costly, so taking more worms, I ven- 
tured to ask him if he would sell me a 
dollar's worth of the plant, at the same 
time displaying my dollar with a hole in 
it ; but he could not spare any without up- 
setting the " balance." 
Where did he obtain it? 
He thought it came from Long Island, 
and could sell a good deal of it if he could 
obtain it. 
What was the name of it? 
Eanunculiis aquat'iUs. 
Would he please write it down, and 
didn't he know of an easier name? So he 
wrote, "Common name — White crowfoot; 
scientific name— Banunculus aquatilis ; is 
semi-aquatic; flowers in June; found 
growing in ponds on Long Island." 
I said thank you, good day, and left 
with a feeling of fullness. Here was more 
light or more darkness on the subject of 
plants. 
That afternoon Mr. Emerson noticed me 
reading the paper over and over, looking 
very much puzzled, and being very quiet ; 
at last he asked me what was the matter, so 
I laid the whole case before him. I then 
learned that all plants have both a com- 
mon and a scientific or botanical name ; 
that the scientific name is the same all 
over the world, and that the common 
name is that by which it is known in 
th^ common language of the country or 
locality. For instance, the Bmmnculus 
aquatilis belongs to the family of butter- 
cups, and bears a strong resemblance to 
our field buttercup when growing out of 
the water; and for this reason I have 
linown it to be called the water-buttercup, 
which I think is a much better name than 
the common name it bears in England, of 
crowfoot, as its leaves are but a poor sug- 
gestion of a crow's foot. Still that is the 
common name it goes by with English 
botanists, who first described and classi- 
fied it. He also informed me that " semi- 
aquatic" meant growing or adapting it- 
self either to land or water. 
About this time I was given two weeks' 
vacation, and determined to invest all my 
dollar in visiting the ponds of Long 
Island, till I found the crowfoot. In this I 
was successful, and soon sold five dollars 
worth, with which money my first glass 
case (or, as I learned to call it, aquarium,) 
was paid for. 
Dealers in stock began to spring up in 
all parts of the city, and the demand for 
aquatic or water plants increased daily, so 
that I found it profitable, as well as 
healthful and pleasant, to go into the 
business, and get back to the woods and 
flowers. 
Every variety of plant I obtained was 
thoroughly tested to ascertain its oxygen- 
ating qualities ; in this way I soon became 
an expert on j)lants and their habits, and 
orders came in faster than I could fill 
them, so that in a short time the dollar 
that I had first expended in search of 
plant knowledge was multiplied many 
times. 
Dealers in aquatic plants are still telling 
the same old vague story of so many 
years ago, " You don't have to change the 
water, because the plants keep it pure." 
They sel'dom inform their customers why 
or how the plant life sustains the animal 
life contained in the aquarium, and very 
many of them do not know and do not 
care. I know a dealer who sells hundreds 
of bunches of plants a year ; one day I 
asked him, in a careless, off-hand way : 
" W , what on earth is carbonic acid 
gas?" His reply was that he neither 
knew nor cared what " carbolic " acid gas 
was. In his establishment are many 
varieties of plants ; some ot them are of 
no value, but they possess a bright green 
color, and sell well, and rot well when 
placed in an aquarium, so that after a be- 
ginner has bought several lots of these 
plants, he gives up in despair Many 
dealers say they do not want the plants 
and fish to live too long, as they cannot 
sell as much stock. 
