12 
SCIENCE. 
Notes and Queries. 
[i.] I am studying the character and extent of a substance 
called “Tuckahoe, or Indian Bread,” for its Ethnological 
interest. I find that my knowledge of Botany is not suffi- 
cient, and desire reliable information upon the following 
points : 
What is the nature of its growth and production ? 
What is its geographical distribution ? 
Its former use and preparation? 
In what kind of soil is it found ? 
What authors have mentioned it ? 
By what botanical names is it known ? 
Has it any medicinal properties? 
J. H. G. 
GENERAL NOTES. 
Formation of Vinegar by Bacteria. — E. Wurm has in- 
vestigated this matter, and his results prove, without doubt, 
that an active formation of vinegar from alcohol is obtained 
by means of Mvccderma aceti (Bacterium mycoderma — 
Cohn), thus supporting Pasteur’s view. 
Organisms In Beet Sap. — The bodies known as "frog- 
spawn," which make their appearance after a time in the 
sap of the beet root, prove, on microscopic examination to 
be a species of bacterium, called by L. Cienkowski, As- 
coccus Bilrothii. 
Ptyalin and Diastase. — T. Defresne has found that 
ptyalin converts starch into sugar, in the presence of im- 
pure gastric juice, as rapidly as it does in the mouth. Its 
action is, however, suspended by pure gastric juice ; but 
on passing into the duodenum the ptyalin again becomes 
active. Diastase, on the other hand, is completely deprived 
of its power of converting starch into sugar by hydrochloric 
acid or by pure gastric juice. (Compt. Rend., 89, 1070.) 
Abnormal Composition of Milk. — According to C. 
Marchaud (Bied. Centr., 1872, pp, 769-770), the usual 
composition of human milk is as follows : Putter, 36.8 ; 
lactose, 71. 1 ; protein, 17 ; salts, 2.04, and water, 873 parts 
per thousand. When the amount of butter rises to above 
52 parts, the milk is injurious to the child. The quantity 
of protein, which is much less than in cow’s milk, cannot 
be exceeded without ill effects. 
Nutritive Value of Grass at Various Stages of 
Growth. — E. von Wolff and others (Bied. Centr., 1879, 
pp. 736-744) cut grass three times in the early summer, in 
the years 1874 and 1877 ; the first cutting took place about 
the middle of May, the second at the beginning and the 
third at the end of June. The second cutting appeared to 
give the best results in the case of animals experimented 
upon, namely sheep and horses ; and, as a rule, it was 
found that more nitrogenous matter was excreted by the 
latter than by the former. 
Analysis of two Ancient Samples of Butter. — G. 
W. Wigner and A. Church have examined a sample of 
Irish bog butter, which cannot be traced with any certainty 
to a particular locality. There is no doubt, however, that 
it is a perfectly authentic specimen, probably 1000 years 
old. The following results were obtained : volatile fatty 
acids, calculated as butyric, 6 per cent ; soluble fatty acids, 
not volatile, 42 per cent ; insoluble fixed fatty acids, 99.48 
per cent ; glycerol, minute traces. The insoluble latty 
acids contained 9 per cent, oleic acid, and 91.0 per cent 
stearic and palmitic acids. 
The other sample of butter, which is much older, was 
taken some time ago from an Egyptian tomb. It dates 
from about 400 or 600 years before Christ. It was contained 
in a small alabaster vase, and had apparently been poured 
in while in a melting state. In appearance, color, smell 
and taste, it corresponds closely with a sample of slightly 
rancid butter. Analysis shows that the sample has not 
undergone any notable decomposition. 
Chloride of Platinum. — Dissolve the metal in hydro- 
chloric acid, 5 parts ; and nitric acid 3 parts — a fiorence 
flask is convenient for this purpose. When all the metal is 
dissolved transfer the solution to a porcelain evaporating 
dish, and apply heat until nearly the whole of the acid is 
expelled. Dissolved in water or in ether chloride of 
platinum is useful for imparting to brass articles a steel like 
appearance. 
The Effect of Carbonic Acid in the Air upon Crops. — 
According to M. Marie-Davy, (Compt. rend. 90, pp. 32-35), 
an examination of the determinations of the amount of car- 
bonic anhydride in the air, which have been made daily dur- 
ing the last four years at Montsouris, seems to show that the 
best crops have been produced in those years when the 
amount of carbonic anhydride has been below the average. 
The carbonic anhydride varies inversely with clearness of 
the sky, and is influenced by the oscillations of the great 
equatorial atmospheric currents. 
Respirative Power of Marsh and Water Plants. — It 
is a well-known fact that these plants are able to thrive in 
media which contain little or no oxygen. They are all very 
poor in nitrogen, and E. Freyberg has shown by a number 
of experiments, that this latter property accounts for the 
former. His investigations prove that the respirative power 
of plants varies with the amount of nitrogen they consume, 
and this, taken in conjunction with the fact that water-plants 
contain large air chambers which do not often need refill- 
ing, accounts for their being able to exist in media which 
contain very little oxygen. 
A railway break, which is instantaneously applied and 
continuous in its action, and which the inventor proposes to 
render automatic, is described by M. Hospitalier in La 
Nature. It is worked by means of two of the secondary bat- 
teries of M. Plante, each of these being charged by three 
Daniell cells. The action of the apparatus is dependent 
upon the adhesion of an electro-magnet to the axle of the 
wheels, by means of which two chains attached to levers 
carrying friction blocks, are wound upon a drum. 
Artificial Diamonds. — In regard to the successful work 
of Mr. Hannay, of Glasgow, in producing perfect artificial 
diamonds, it may be well to bear in mind the similar in- 
vestigation carried on by Despretz, the noted French 
chemist. Some authorities allege that the results obtained 
by Despretz were in advance of those reached by Mr. 
Hannay, yet the former, at the conclusion of five years of 
labor, made the frank acknowledgment that he had not 
found the diamond proper, although he had obtained crys- 
tals of pure carbon possessing all the characteristics of the 
coveted prize. 
Cyanide of Potassium. — There are many substances 
which are difficult to procure, whereas the materials of 
which they arecomposed are within the reach of every- 
body. To make Cyanide of Potassium, use the following 
formula : 
Yellow prussiate of potash 8 parts. 
Carbonate of potash 4 parts. 
Reduce the prussiate of potash to a coarse powder, and 
dry upon an open plate over a slow fire ; next dry the car- 
bonate of potash thoroughly, when both substances are to 
be intimately mixed. Put the mixture in a crucible or deep 
iron ladle, and place in a clear burnt coke fire. When 
fusion takes place, stir occasionally with an iron rod. 
When the mass is thoroughly fused allow it to continue in 
that state for at least a quarter of an hour. If on dipping 
the iron rod into the melted mass the compound appears 
white on cooling, the ladle may be withdrawn from the fire, 
allowed to rest for a few minutes, when the cyanide which 
is formed, must be poured in patches on an iron slab or 
flagstone, care being taken not to allow the dross, which is 
chiefly iron, to pass out with the clear fused cyanide. The 
"dross” should be shaken out separately, and when cold 
washed with water to dissolve out the adherent cyanide, 
after which the washing water may be filtered and used as a 
solution of cyanide when required. Keep the cyanide in a 
wide mouth bottle well corked, and labelled. 
