This vital fact is the key to the injurious results developed in the kidneys by the use of alcoholic drinks.  These two organs have large blood-vessels conveying full amounts of blood to and from their structures, and they feel very quickly the presence of alcohol.  Alcoholic liquors excite and irritate the delicate renal membranes, and speedily disturb and eventually destroy their capacity to excrete the proper materials from the blood.

The continued congestion of the minute structure of the kidney cuts off the needed nutrition of the organ, and forms the primary step in the series of disasters.  Sometimes from this continued irritation, with the resulting inflammation, and sometimes from change of structure of the kidney by fatty degeneration, comes the failure to perform its proper function.  Then, with this two-edged sword of disaster, the urea, which becomes a poisonous element, and should be removed, is retained in the system, while the albumen, which is essential to healthy blood, is filtered away through the diseased kidney.

259.  Alcoholic Liquors as a Cause of Bright’s Disease.  The unfortunate presence of albumen in the urine is often a symptom of that insidious and fatal malady known as albuminuria or Bright’s disease, often accompanied with dropsy and convulsions.  One of the most constant causes of this disease is the use of intoxicants.  It is not at all necessary to this fatal result that a person be a heavy drinker.  Steady, moderate drinking will often accomplish the work.  Kidney diseases produced by alcoholic drinks, are less responsive to medical treatment and more fatal than those arising from any other known cause.[39]

Experiment 129.  Obtain a sheep’s kidney in good order.  Observe that its shape is something like that of a bean, and note that the concave part (hilus), when in its normal position, is turned towards the backbone.  Notice that all the vessels leave and enter the kidney at the hilus.  Observe a small thick-walled vessel with open mouth from which may be pressed a few drops of blood.  This is the renal artery.  Pass a bristle down it.  With the forceps, or even with a penknife, lift from the kidney the fine membrane enclosing it.  This is the kidney capsule.

Divide the kidney in halves by a section from its outer to near its inner border.  Do not cut directly through the hilus.  Note on the cut surfaces, on the outer side, the darker cortical portion, and on the inner side, the smooth, pale, medullary portion.  Note also the pyramids of Malpighi.

Chapter X.

The Nervous System.

260.  General View of the Nervous System.  Thus far we have learned something of the various organs and the manner in which they do their work.  Regarding our bodily structure as a kind of living machine, we have studied its various parts, and found that each is designed to perform some special work essential to the well-being of the whole.  As yet we have learned of no means by which these organs are enabled to adjust their activities to the needs of other tissues and other organs.  We are now prepared to study a higher, a more wonderful and complex agency,—­the nervous system, the master tissue, which controls, regulates, and directs every other tissue of the human body.