The Courage of Dr. Hall

Courage, mental and physical, also counts in farm science. Millions of people in tropical and subtropical parts of the world have been freed of the dread hookworm disease because courageous research men found new ways to protect livestock from injurious parasites. In searching for effective treatments for hookworms of livestock, Maurice C. Hall saw references to chloroform described as giving fair results. This led him in 1921 to try carbon tetrachloride, a related chemical that was cheaper. But was it safer than chloroform? Was it better for the purpose? Dr. Hall had to know. He tried his new treatment on various animals, but there was still a question of its safety for human use. So he took doses of it himself on three occasions to test its reaction. He suffered no harmful effects, and in a short time carbon tetrachloride was being used widely in both human and veterinary medicine.

A few years later Hall and his coworker, J. E. Shillinger, discovered that tetrachlorethylene was even better than carbon tetrachloride for treating dogs infested with hookworms. Again Dr. Hall took his own medicine with no ill effects. It soon replaced the earlier treatment.

There is no way to evaluate a discovery of this kind. No one knows how many animals, including man's good friend the dog, have been freed of hookworms. It is estimated that at least 15 million persons have benefited from the treatments that Dr. Hall first developed for livestock.

Like Hall, Henry Ayers was a great benefactor of mankind. Probably no work ever done in-the Department, or anywhere else for that matter, has had a more profound effect upon the health of United States citizens than that of S. Henry Ayers, a bacteriologist. His work, and that of his associates, laid the ground work for present-day sanitary regulations governing the handling and pasteurization of -milk.

It may be surprising to many to learn that there was much opposition—even among scientists and doctors—to the pasteurization of milk even as late as 1910. The practice was first recommended as a health measure in 1875, but many people in positions of responsibility believed that it would do more harm than good. They argued that pasteurization destroyed the lactic acid bacteria in milk, causing it to putrefy instead of souring. It was also thought that destruction of the lactic acid bacteria allowed the growth of undesirable organisms that produced toxins that made pasteurized milk unfit for human consumption.

Ayers made a painstaking study of milk, recording the presence of bacteria in raw and pasteurized milk obtained from retail outlets of several cities. He made thousands of counts of bacteria. His work, first published in 1910, showed that pasteurization did not destroy all of the lactic-acid-forming bacteria, that organisms did not multiply faster in mil) that had been pasteurized, and that pasteurization merely prolonged the condition of clean raw milk. His publications convinced many physicians and public officials that pasteurized milk was safer than raw milk. These publications take their place beside the most illustrious ever issued by the Department. His work shows another facet of our tradition--the value of persistent, careful, maybe slow, progress toward the goal.

So does the work of L. A. Rogers and C. E. Gray, to whose painstaking research we owe, in large degree, the quality of our butter. Rogers and Gray devoted a good share of their time for 10 years, beginning in 1902, to improving the storage quality of butter.

When their work began, almost all butter was made from raw, sour cream. This had been the practice for centuries, and it was common belief that high acidity of the cream was necessary to insure desirable flavor in the butter. Butter held in cold storage usually developed off-flavors, but these were thought to be a result of bacterial action.

Rogers and Gray spent many months making bacteriological studies but were unable to find any bacteria that would cause the undesirable flavors. What they did find was that butter that developed the bad flavors almost always had been made from sour cream, and that such flavors never occurred in butter made from pasteurized sweet cream.

By 1907 Rogers and Gray had ample proof that most of the deterioration in storage butter was a result of chemical changes, promoted by the presence of acids, that bacteria were only indirectly concerned, and that butter of good flavor and superior keeping quality could be made from pasteurized sweet cream.

Their discovery revolutionized the practice of making creamery butter and opened up a new field of investigations that have resulted in improving the keeping quality of all fat-containing dairy products.

We in agricultural research inherit also a tradition of simplicity—the mechanisms and bases of our studies often are technical and involved, but the result, to be useful, must be simple, clear, workable. The best example I know of is the Babcock test for butterfat.

Many scientific discoveries, inventions, and ideas have contributed to the advancement of the dairy industry in the past half century, but no other single discovery has done so much to advance dairy science or remained so universally in continuous use as the Babcock test.