288 



THE POPULAR SCIENCE MONTHLY. 



its surface is 212 metres (689 feet) below 

 the level of the Mediterranean, and that 

 its greatest depth, which is at the northern 

 extremity opposite the upper mouth of the 

 Jordan, is 250 metres (812 feet). On both 

 shores of the lake are terraces covered 

 with rounded pebbles, rising to a height 

 which indicates that the level of the lake 

 was once the same as that of the Mediterra- 

 nean. He believes that the waters of the 

 lake were formerly very salt, more so than 

 sea-water, but not so excessively salt as the 

 waters of the Dead Sea, and that they have 

 been freshened since the level of the lake 

 was lowered by volcanic convulsions, by the 

 flow of the Jordan, till they have become 

 drinkable. 



Professor Schneltzler, assuming that 

 the color of flowers is due to the combina- 

 tion of different chemical elements in their 

 tissues, has shown by experiment that when 

 an alcoholic extract of the color is made it 

 is enough to add to it an acid or alkaline 

 substance to cause it to exhibit any of the 

 colors which plants present. Flowers of the 

 peony, for example, give a violet liquid in 

 alcohol; if salt of sorrel is added to this 

 liquid, it will turn a pure red ; soda pro- 

 duces, according to the quantity that is 

 added, violet, blue, or green. 



Those in pursuit of the marvelous may 

 learn a grain of caution from the following, 

 taken from an article on " Living Toads in 

 Stone " by Mr. Thomas G. Denny, in a recent 

 number of " Science Gossip " : " Most of us 

 have heard of ' Flint Jack,' but I do not 

 think many readers of this journal have met 

 with any manufacturers of fossil toads ; but 

 I knew many years ago a working naturalist 

 living in Leeds who used to prepare for sale 

 toads, stated to have been found in beds of 

 coal, by baking them perfectly black and 

 hard in an oven, and then taking square 

 pieces of coal and, after splitting them care- 

 fully, he would cut a hollow in each portion 

 to receive the ' ancient reptile.' " 



5Ir. Frederick Ransome has succeeded 

 in producing a good hydraulic cement from 

 the slag of blast-furnaces. His process, 

 which is applicable to almost any quality of 

 slag, has the advantage over previous meth- 

 ods of making cement, that while in them 

 the materials, lime, silica, and alumina, had 

 to be brought together and carefully com- 

 bined, in blast-furnace slag the combination 

 has already been completely effected before 

 the slag has left the furnaces, and generally 

 with the proportions of silica and alumina 

 that are required. By mixing the slacc with 

 an additional quantity of lime and calcining 

 the mass, a strong and reliable cement of an 

 agreeable color is produced. 



It has been affirmed, in proof of the the- 

 ory that fat is formed from albumen, that 

 the albumen of the cheese in the cellars of 

 Roquefort is changed to fat by the action of 

 a fungus found there. The assertion is dis- 

 proved by experiments made by Herr Sieber 

 on the cheese in these cellars, which show that 

 the most marked change that cheese under- 

 goes in ripening is the loss of water, and 

 that the proportion of fat remains unaltered 

 if only the dry substance be considered. A 

 decomposition of the albumen also takes 

 place, the caseine passing into a series of de- 

 composition-products which are similar to 

 products of putrefaction in the first stage of 

 putrefactive fermentation, but the analyses 

 show no transformation of albumen into 

 fat. 



Efforts to reduce monkeys to discipline 

 have not very often been successful. A na- 

 tive of the province of Bengal has, however, 

 trained several of them to work the cords 

 by which the punka, or ventilating fan of 

 India, is moved. They perform their task 

 to perfection, and, thanks to their activity, 

 keep the jDMX:os in continuous motion, main- 

 taining a constant, agreeable movement of 

 air all through the room. 



Dr. Henry Barnes records a case of an 

 extremely severe attack of gout brought on 

 by sleeping in a newly painted room. Three 

 years before, the patient, an old man, had 

 suffered a slight attack of the disease (the 

 first of his life), but soon recovered, and, up 

 to the time of this exposure, had been quite 

 free from gouty symptoms. The introduc- 

 tion of lead into the system is given as 

 the cause of the attack. 



A COMPANY with large capital has been 

 formed in Paris to woi-k up an invention for 

 coating thread with silk. The invention em- 

 braces, according to the " Bulletin des Soies," 

 a chemical process for covering linen or 

 other vegetable threads with amesh of silk- 

 en matter in a manner siinilar to that in 

 which metallic objects are plated with gold 

 or silver. The process is dependent on the 

 fact, which has long been known, that silk 

 is soluble in several strong acid prepara- 

 tions. 



The French Chamber of Deputies has 

 voted a credit of fifty thousand francs to 

 M. Pasteur to enable him to extend his re- 

 searches upon the contagious diseases of ani- 

 mals. The labors of M. Pasteur during the 

 last four years have already led to the dis- 

 covery of the causes of carbonaceous affec- 

 tions, and the knowledge thus gained has 

 been employed to prevent them in many 

 cases. His present investigations are in re- 

 lation to the character of virulent maladies 

 in general. 



