medical, and not hostile to the French troops.  The husband discovered that his wife had been in labor for thirty-six hours.  Labor was slow and the contractions weak and far apart.  He had thought it advisable to provoke speedy contraction, and, following the Algerian custom to scare the baby out, he had fired the musket near his wife’s ear; instantanously the accouchement was terminated.  After being imprisoned twenty-four hours, the Arab was released.”—­Cincinnati Lancet.

* * * * *

“ELASTIC LIMIT” IN METAL.

The Engineering and Mining Journal raises the question whether steel, which is becoming so popular a substitute for wrought iron, will, when it is subjected to continuous strain in suspension bridges and other similar structures, do as well as iron has proved that it can.  Recent tests of sections from the cables at Fairmount Park, Philadelphia, and at Niagara Falls show that long use has not materially changed the structure.  The Journal says:  “It is a serious question, and one which time only can completely answer, whether steel structures will prove as uniformly and permanently reliable as wrought iron has proved itself to be.  In other words, whether the fibrous texture of wrought iron can be equaled in this respect by the granulated texture of steel or ingot iron.  In this connection it is interesting to note that the fibrous texture referred to is imparted to wrought iron by the presence in it of a small proportion of slag from the puddling furnace, and that this can be secured in the Bessemer converter also if desired.  The so-called Klein-Bessemerei, carried on at Avesta in Sweden for several years past, produces an exclusively soft, fibrous iron by the simple device of pouring slag and iron together into the ingot mould.  This requires however a very small charge (usually not more than half a ton), and a direct pouring from the converter, without the intervention of a ladle, which would chill the slag.”

The effect of the introduction of slag would seem to be to retrace the steps usually taken in producing steel, viz., to separate the iron from its impurities, and then to add definite quantities of carbon and such other ingredients as are found to neutralize the effects of certain impurities not fully removed.

The most intelligent engineers, after ascertaining by exhaustive physical tests what they need, present their “requirements” to the iron and steel makers, whose practical experience and science guide them in the protracted metallurgical experiments necessary to find the exact process required.  The engineer verifies the product by further tests, and by practical use may find that his “requirement” needs further modifications.  As a result of all this care, some degree of certainty is secured as to what the material may be expected to do.

No doubt the chemical composition of the slag used at Avesta was known and met some equally well known want in the iron, and thus the result arrived at was one which had been definitely and intelligently sought.