672 
UTILIZATION OF SEWAGE. 
while the attention of naturalists was drawn to these objects, 
“whose phosphorescence was remarkable even among ^the 
fiery waves of the intertropical ocean,” and they sometimes 
discovered them in an isolated condition, and sometimes in 
chains. It was Chamisso who explained this riddle. He 
saw that the Salpae were androgynous (bisexual) and vivi¬ 
parous; that they came into the world in the shape that they 
preserved all their lives; and that, strange to say, a solitary 
mother only brought forth infants united in colonies, and 
these in their turn engendered only solitary individuals. It 
followed from this that a salpa never resembled its mother 
or its son, but always its grandfather or its grandson.” 
Upon this curious state of things, M. Quatrefages remarks 
that (( metamorphosis here influences generations and not 
individuals, and matters proceed as if the caterpillar, instead 
of becoming transformed, gave birth to complete butterflies, 
which in their turn reproduced the caterpillars.” 
(To le continued .) 
UTILIZATION OF SEWAGE. 
To this subject we directed the attention of our readers in 
a previous number, under the heading of Carbolic acid as a 
disinfectant , deodorizer , and therapeutic. 
It is gratifying to know that no less a personage than the 
Earl of Derby has considered the matter not beneath his 
notice. At the late meeting of the North Lancashire Agri¬ 
cultural Society, firstly adverting to the advantages derived 
from machinery in connection with science, he says:—“ We 
are gradually finding out, and it is an important discovery 
for this country, how entirely and closely mechanical and 
chemical science are connected with the material interests of 
agriculture. Day by day we are becoming more and more 
indebted to science for the progress which we are making, 
by the largely increased purchase of those implements, 
without which they would not be shown, the farmers 
of this country thus showing their practical appreciation 
of the vast advantages which they derive from them. 
Why, gentlemen, it is only within a very few years that we 
have even heard of such a thing as a steam-threshing machine, 
yet steam is now, not rapidly perhaps, but certainly, making 
progress as one of the most important elements to be applied 
to the cultivation of the land. There is no description of 
