The inorganic laboratories, for elementary purposes, may be divided into three principal divisions: first, that devoted to the study of the simple reactions by the beginner, who there learns experimentally what takes place in the simple reactions, as that of the production of hydrogen gas by pouring sulphuric acid on zinc, forming zinc sulphate and liberating the gas. The second division is that part devoted to qual itative analysis, where more complex reactions are studied and where the student learns to recognize and to test for the presence of the different elements. Under the third division is found quantitative analysis, which, as the name implies, is devoted to the study of the quanti tative relations of compounds.
The work in these three divisions leads up to the more complex work of organic chemistry and research work. The equipment of these laboratories will give a general outline of the 'whole. Wide top tables should be provided. The tops should be impervious to water and as little acted on by acids as possible. Alberene stone is excellent material for such purposes. A good construction is to have the tops slope a little from both sides to the centre line, where a trough is placed to carry off the wastes to the sewer. Racks for the storing of bottles contain ing reagents should be placed so as to be easily reached by the students from both sides of the table. Beneath the top should be drawers and shelving so subdivided that each student may keep his apparatus separate. The tables should be provided with as and water, with plenty of taps and with electrical connections. Means should also be furnished for boiling tinder reduced pressure. For the experiments where noxious gases are given off, hoods should be provided, the bases being of the same mate rial as the table tops, the sides and top of fixed glass with a glass window that may be opened in front. For ventilation within the hood there should be openings to a flue connected with a blower which produces a suction of the gases from the hood. One of the openings should be well toward the top and the other at the bottom of the hood. If artificial lighting is required it should be from above the glass top. Plenty of stop-cocks for gas, water and suction should be provided for each hood.
Among the independent rooms needed are those for the following purposes: A hydrogen sulphide plant is an absolute necessity, and it should be isolated to the extent of having a wen-ventilated room of its own. It should, however, be situated as conveniently as possible to the main divisions of the laboratory. Some times it may be advantageous to pipe the gas to different rooms. Near the quantitative laboratory should be a balance-room well stocked with analytical balances supported on solid tables or wall brackets. A combustion room and a furnace-room are often required. The furnace-room should be so located as to get a good draft or so as to be connected to a suction fan system.
The study of the spectrum of gases makes it necessary to have a good induction coil to produce a spark spectrum, which may be viewed by the eye, or which may be photographed. The range of temperatures at which chemical phenomena are now studied calls for very high and very low temperatures, which means that the electric furnace and a liquid air plant are often desirable. Apparatus for distillation un
der different pressures and for obtaining con stant temperatures are very necessary in some phases of the work. The rooms for gas analy sis should be so situated as to make it pos sible to have but small temperature fluctuations. A north exposure, thus getting rid of direct sunlight and yet getting good illumination, is preferable. The principal part of the equip ment needed for gas analysis by the Hempel method includes gas buretts, to measure vol umes, absorption pipettes for the different re agents used to absorb different gases, com bustion pipettes and oxygen generators.
The 'diernistry laboratory requires much apparatus and equipment needed in phys ics and in the other divisions of chemical work, including analytical balances, thermome ters, barometers, manometers, calorimeters, • thermostats, motors, stirring gear, ref ractom eters, spectrometers, apparatus. for studying polarized light, ammeters, voltmeters, resistances and many other pieces. Among the subjects studied in the student laboratory are density, viscosity, vapor pressure, boiling and freezing points, heats of fusion and vaporization, crit ical temperatures, pressures and volumes, heats of combustion, solubility and the various divi sions of electrolysis and electro-chemistry.
Electrical Laboratory.-- The student and investigator in the field of electricity should have a thorough grounding in general physics and physical laboratory methods. The student in the electrical laboratory becomes acquainted with the relations of electric currents, electro motive forces and resistances; and the pro duction and transmission of electrical energy, electrical quantity, capacity, magnetism and the relations between electricity and magnetism. The laboratory should be of strong construc tion on account of the lines of shafting and the heavy machines used. In the general labora tory will be found for purposes of investiga tion dynamos of the various direct and alter nating current types; direct and alternating current motors, the latter covering synchronous, two-phase and motors, induction motors and rotary converters. Portable and variable inductive and non-inductive resist ances; portable and fixed instruments for meas uring current, electrical pressure or potential and power should be plentifully supplied. The fixed machines, instruments, the private rooms and tables should have lines of wire connecting them with a central switchboard through which any desired grouping of stations may be made. Among the separate departments may be one for testing and studying transformers; one for investigating the magnetic properties of iron, steel and other metals; a potentiometet room in which to test and calibrate the instru ments used in electrical measurements. Some interesting and important parts of the work are the investigation of the resistance and strength of insulators and conductors; the study of condensers and their effect in a cir cuit; the study of self and mutual induction and the measurements of them. Separate rooms which can ibe made dark, the walls of which absorb as much light as possible, or which can be made any color desired by a prover arrangement of coverings, where work in light ing and photometry may be performed, are also important parts of the equipment of an electrical laboratory.