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 Myccderma 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 : butter, 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 tatty 

 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 florence 

 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. 



