Proceedings of the Polytechnic Association. G95 



The following notes on scientific progress were presented by tlie 

 Chairman : 



Castii^g Steel under High Pressure. 



Mr, G-aly Cayalat of France has invented a process for making 

 sound steel castings by means of gaseous pressure applied to the 

 metal as soon" as it is poured into sand molds inclosed in iron flasks. 

 The pressure is generated by exploding about a quarter of an ounce 

 of a powder consisting of eighty parts of saltpeter and twenty parts 

 of pulverized charcoal. It is said the invention has been successfully 

 applied in France in the casting of steel cannon. 



Ye^-om of Toads. 

 Experiments made with toads by Gratiolet Gloez and Yulpian 

 prove that matter is exuded near the ear which is poisonous when 

 introduced into the tissues of other animals. Dogs, after biting a 

 toad, show signs of pain. But the bite of the toad is not poisonous. 

 It is said some Indians in South America use a fluid obtained from 

 the back of the toad, in place of curara, for poisoning the tips of 

 their arrows. The ordinary toad may be handled with impunity, 

 but should the secretion alluded to come in contact with abraded skin 

 unpleasant sensations might ensue. 



A ]^Ew Disease. 



Dr. Duchenne of France has described a new malady found only 

 among children- and 3'oung persons. It commences with a partial 

 paralysis indicated by feebleness and unsteadiness in movement, 

 which, if not then checked by proper remedies, is followed by 

 an unnatural enlargement of the muscles usually', first in the calf 

 of the leg, then by a general paralysis, when death ensues. He has 

 extracted, by means of an emporte-inece or nipping tool of his own 

 invention, portions of the muscle which, on examination, are found 

 to contain, in the first stages of the disease, an undue proportion of 

 fibrinous matter, and afterward a fatty deposit. 



Letter Book. 

 Messrs. P. Garrett & Co., of ^o. 702 Chestnut street, Philadelphia, 

 maiiufacture a letter press copy book for taking instantaneous copies- 

 of manuscript, wliich has been found to answer in the best manner 

 the purpose for which it is intended. A sympathetic ink is used with 

 the paper of such a consistency and character that when a page of 



