P. CAZENEUVE publishes in the _Comptes Rendus_ a new method for the preparation of acetylene, which consists in mixing iodoform intimately with moist and finely divided silver. An abundant evolution of acetylene takes place without heating. The reaction is represented by the following formula: 2CHI_{3} + 6Ag = C_{2}H_{2} + 6 AgI. The decomposition of the iodoform is hastened if the silver is mixed with finely divided copper, such as can be obtained by precipitating it from its sulphate by means of zinc. Cazeneuve also observed that most metals which have any affinity for iodine will decompose iodoform in the presence of water, forming acetylene and an iodide of the metal. By the use of zinc he obtained a liquid having a pleasant ethereal odor, and a gas mixture that contained besides acetylene an iodine compound which burned with a purple-edged, fawn-colored flame. * * * * * WHEN DOES AN ELECTRICAL SHOCK BECOME FATAL? In this age of electricity and electric wires carrying currents of various intensity, the question of danger arising from contact with them has caused considerable discussion. An examination into the facts as they exist may therefore enlighten some who are at present in the dark. To begin with, we often hear the question asked--why is it that certain wires carrying very large currents give very little shock, whereas others, with very small currents, may prove fatal to those coming in contact with them? The answer to this is--that the shock a person experiences does not depend upon the current _flowing in the wires_, but upon the current _diverted from them_ and _flowing through the body_. The muscular contraction due to a galvanic current, which was first observed in the frog, gives a good illustration of the fact that it requires only a very minute current to flow through the muscles in order to contract them. Thus the simple contact of pieces of zinc and copper with the nerves generated current sufficient to excite the muscles--a current which would require a delicate galvanometer for its detection. What is true of the muscles of the frog holds good also for the human muscles; they too are very susceptible to the passage of a current. In order to determine the current which proves fatal we need only to apply the formula which expresses Ohm's law, viz., C=E/R, or the current (ampere) equals the electromotive force (volt) divided by the resistance (ohm). According to the committee of Parliament investigation, the electromotive force dangerous to life is about 300 volts; this then is the quantity, E, in the formula. There remains now only to determine the resistance in ohms which the body offers to the passage of the current. In order to obtain this, a series of measurements under different conditions were made. On account of the nature of the experiment a high resistance Thomson reflecting galvanometer was used, with the following results.