out-prove advantageous; not only to consumers, but to honest traders, who are often unfairly beaten in competition at fixed prices by those who are less scrupulous :

1. Goods tendered for in supplying gaols, workhouses, prisons, and public institutions, should be periodically tested and compared by the public analyst.

2. Public analysts should be authorized themselves to examine such suspicious articles as may come from time to tiine under their notice.

The following simple principles should guide the magistrates in dealing with offences under the act:

1. The presence of harmless substances which may be regarded as accidental impurities, should not be punishable unless present in fraudulent proportions.

2. Fraudulent adulteration should be heavily visited as allowed by the act. The retail dealer may protect himself from the consequences of the acts of others by getting guarantees from the wholesale dealer.

3. Adulterations by means of dangerous substances should be punished as heavily as the law will allow.

This is not the time to speak in detail of the manner in which the public analyst has to carry out his duties. I may say, however, that his qualifications ought to be-and I think generally are-most rigidly inquired into before his appointment; and that an accused person has always the opportunity of having a check analysis made on a portion of the sample taken if he feels aggrieved.

The modes of detecting adulteration are either mechanical, chemical, or microscopic-although sometimes these different modes may be combined. The results are frequently checked by comparison with those similarly obtained from articles of known purity. Some of the processes are simple and require no delicate

manipulation, but frequently time, patience, and skill are all required.

or

The lecture was concluded with a few illustrations of what were termed Simple Tests for Common Adulterations; modes of detecting the adulteration of milk with water; coffee with chicory; mustard with turmeric and starch; anchovies, anchovy paste with oxide of iron and red lead; beer with salt or sulphate of iron; vinegar or gin with sulphuric acid; and some others were fully illustrated by the lecturer, and the precautions necessary to prevent mistakes in reading the results were minutely dealt with.

TANGYE'S HYDRAULIC WORKSHOP APPLIANCES.

These consist of "lifting Jacks," "pulling Jacks," and "punching Bears ❞—all exceedingly light, convenient and portable, and possessing very considerable power.

Lifting Jacks, of only 23′′ height and weighing but 57 lbs, are capable of lifting four tons, while 60 tons may be lifted by a machine only 5" higher and weighing little over three cwt.

The Hydraulic Punching Bear, which may, if necessary, be worked by only one man, will punch a 14 hole cleanly through a 1′′ plate of iron-the machine itself weighing less than three cwt. Smaller sized machines are made for smaller work. These machines are, from their compactness and comparative inexpensiveness, well suited for use in small workshops where powerful punching machinery is only required occasionally, and where it would not pay to keep a steam punch long idle.

The details of these lifting-jacks and punching bears are fully illustrated on Plate XIII, Figs. 1 to 5.

Figs 1 and 2 represent a convenient form of lifting-jack—Fig. 2 being a section. The cistern a contains water, which may contain a very small portion of carbonate of soda to retard rust. The water is charged into the cistern by the screw g which is relaxed while working to admit air, and tightened up when the jack is done with to prevent loss of water. The working lever is shewn at the side and this gives alternate motion to the pump piston c in the pump d; e is the inlet valve, covered with wire guaze to prevent the entrance of dirt; f is the cylinder which

receives the water forced by the pump d; h is the ram which is forced down by the accumulation of water in f, so increasing the total length of the jack and raising any weight which may be placed above its upper surface, the lower being fixed. By turning the lever k the water passes from ƒ to a and the weight is lowered

at once.

The Hydraulic Punching Bears are illustrated in Figs. 3, 4, 5, Plate XIII. Fig. 3 shows the whole machine mounted upon three moveable legs, which may be detached when it is necessary to use it in a confined situation. It is worked by the upper lever and the punch is raised by the lower lever. The construction and mode of working are shewn in Figs. 4, 5, and are precisely similar to the working of the jack already described the only difference being that a punch is attached to the lower end of the ram which

FIG. 2

FIG. 1

works in a steel die the size of the hole to be made. The letter ing of similar parts in Figs. 4 and 5 is similar.

Sometimes the

cistern of the punching bear is filled · The motion is then generally smoothe what more likely to get out of order.

Tangye's Self-sustaining Pulley Blo cuts Figs. 1 and 2, on the preceding p arrangement of a double-sheaved uppe eccentric brake A on a larger scale.

A somewhat similar contrivance has a chain block, but this is the first app of the sort to a rope block. It is selfput in and out of action by a simple n to the right or left, or by pulling the the blocks the hand-rope may be pulle will release the brake, when the rop freely as desired.

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