8o 



SCIENTIFIC NEWS. 



[Jan. 27, iS 



hours will suffice. The solution of chloride of tin must 

 not contain too great an excess of acid, otherwise it will 

 attack the iron itself After the articles have been removed 

 from the bath, they should first be washed in water, 

 then with ammonia, and dried as quickly as possible. 



Rubber Tubing. — Very elastic caoutchouc tubing 

 gradually loses some of its elasticity. Later, the tubes 

 break on stretching, even if previously laid in warm 

 water, and, finally, they crack if pressed between the 

 fingers. This change is put down to a very slow forma- 

 tion of sulphuric acid by the action of moist air on the 

 sulphur contained in the caoutchouc. By frequent wash- 

 ing with alkaline water, the action of the acid is prevented. 

 Tubes washed five or six times a year remain perfectly 

 elastic. 



Danger from Perforated Iron Masts. — In a recent 

 case of spontaneous combustion on board a ship laden 

 with coal, flames were seen issuing from the heads of the 

 fore and main masts. These were made of hollow iron, 

 and for the purpose of ventilating the hold they had been 

 fitted with perforations below deck. Consequently, as 

 soon as fire broke out in the hold, these masts acted like 

 chimneys, and greatly increased the fury of the fire. It 

 will therefore be necessary to devise some method 

 of closing and opening such ventilators at will, so as to 

 cut oft" the draught. 



Alumina naturally present in Wheat.— Mr. Rashida 

 has recently communicated to the Chemical Society a 

 paper on " Aluminium in the Ash of Flowering Plants," 

 showing that alumina is a normal constituent of wheat 

 and the other cereals. This interesting question has been 

 recently re-examined by Mr. W. C.Young, F.C.S., who 

 not only confirms the results of Mr. Rashida, but shows 

 that the whole of the alumina in wheat is contained in 

 the gluten. This is an important fact, since it has been 

 generally concluded that alumina did not at all enter into 

 the organism of the higher plants. 



Contamination of Current Coins. — Medical contem- 

 poraries maintain that, of all metals, bronze takes up and 

 retains filth most readily, and prove their point by recit- 

 ing a number of the conditions, unappetising, if not posi- 

 tively dangerous, to which money generally, and bronze 

 pieces in particular, are exposed. We believe that in 

 the last century the " wits " and the " beaux " received 

 their change at fashionable taverns and coffee-houses in 

 washed silver, but no such precautions are adopted in 

 these days of hurry. We must, however, particularly 

 caution our friends never to hold any piece of money in 

 the mouth. 



Famine and Sun Spots. — The Indian Meteorological 

 Department has published a report, in which Mr. Blanford, 

 head of the department, discusses the theory, first started 

 during the Madras famine ten years ago, that famines 

 tend to recur in Southern India at periods when the sun's 

 spots are at the tniniinum of size and frequency. Mr. 

 Blanford comes to the conclusion that there are no suffi- 

 cient coincidences to support this theory. Nevertheless, 

 he says, droughts of more or less severity do visit parts 

 of India not liable to the influence of cyclonic disturb- 

 ances at intervals of ten or eleven years, and the reason 

 cannot be conjectured satisfactorily. The droughts in 

 Northern India are less regular than those in Southern 



India, and they have been observed to be preceded by a 

 heavy snowfall in the North- Western Himalayas. 



The Lowest Observed Temperature. — The Russian 

 Government some time ago established a meteorological 

 observatory at Werchojansk, to the east of the Lena, the 

 coldest district in the empire, according to the isothermal 

 charts. The lowest temperature recorded there was, 

 prior to the establishment of the observatory in Decem- 

 ber, 1871, when the thermometer recorded — 63'2° Centi- 

 grade, which was then the lowest temperature recorded 

 ill the world. On the 3rd January, 1883, the alcohol 

 thermometer registered —68°, as the mean of the month, 

 the lowest on record being — 527°. On reducing the tem- 

 perature recorded by the air thermometer to that of the 

 alcohol thermometer which had been verified at the 

 Central Physical Observatory of St. Petersburgh, the 

 value was found to be —76° C. The reading - 63'2^ C. 

 corresponds with 82" of frost on the scale of the ther- 

 mometer we use in England, — 68' C. with 90°, and 

 — 76" C. with nearly 105" of frost. 



The Colours of Flowers. — The distinguished German 

 botanist. Professor Sachs, has discovered that the ultra 

 violet and invisible rays of the solar spectrum are 

 especially efficacious in the development of flowers. If 

 these rays are suppressed, the vegetative organs grow 

 luxuriously, but the flowers are almost entirely suppressed. 

 The professor thinks that extremely small quantities 

 of one or more substances, formed in the leaves, cause the 

 formative materials which are conveyed to the growing 

 points to take the form of flowers. They act like ferments, 

 so that extremely small quantities of the flower substances 

 act upon large quantities of plastic substances. Assuming 

 there are three distinct regions of the solar spectrum, he 

 shows that these difterin their physiological action. The 

 yellow and adjacent rays cause the decomposition of 

 carbonic acid, and are active in assimilation ; the blue 

 and visible violet rays are the causes of the movements 

 of irritation ; whilst the ultra-violet rays are those which 

 produce in the green leaves the substances out of which 

 flowers are developed. 



The Levant Sponge Fisheries. — Sponge fishing ex- 

 tends all along the coast of Batroon, Tripoli, Latakia, and 

 the Island of Ruad, north of Tripoli. It is not confined to 

 native fishermen, for many Greeks go from Kalimno, 

 Stanchio, Rhodes, and Samos, in their little craft, to 

 share the trade with the Syrians. The fishing boats 

 are generally from i8ft. to 20ft. long, and have a crew of 

 four or five. The season commences in June and extends 

 to October, this season being the most suitable, owing to 

 the calmness of the sea. The boats remain out from 

 sunrise to sunset ; the divers are mostly young and 

 middle-aged men, who remain at the bottom from sixty 

 to eighty seconds at a time. They carry an open net, 

 and use no instruments in collecting sponges. Accidents 

 do not often take place during sponge-fishing. The 

 divers descend to a depth of from 25 feet to 175 feet ; 

 below those depths no good sponges are said to be found. 

 Three kinds of sponges are known in Beyrout — prime, 

 seconds, and the red sponges taken near Batroon. The 

 latter are by far the best. They have to be cleaned, 

 freed from sand, and then pressed. The best quali- 

 ties are exported from Beyrout to Paris direct, the 

 others go almost exclusively to Trieste, while the Greeks 

 send their catch to different markets in Europe, 



