National Historic Landmark

Lafayette B. Mendel House

The Lafayette B. Mendel House is a two-and-one-half story brick building. At the time of the National Register nomination, the architect was unknown, though it has since been learned that the house was designed by Henry Austin. The section of New Haven in which it is located plus its architectural style indicate that it was probably built in the mid-188C's. Architecturally the square form of the building would suggest that it is a vernacular example of the Renaissance Revival style with several Italianate overtones such as the cupola and a small, second story balcony. Some of its features are: an Italianate cupola, a cornice with dentils, an Ionic columned portico, an entrance with sidelights, and a side oriel bay.

The integrity of 18 Trumbull is whole. The exterior, which is well maintained, has undergone no alteration. The interior, a side hall plan, is intact, but some partitioning has taken place in keeping with the building's present function as an accountant's office. Many interior details are still present. There are no significant intrusions. The house was designated a National Historic Landmark in 1976 for its association with Lafayette Mendel, who there from approximately 1900 to 1924, when he and his wife moved to an apartment on Whitney Avenue.

Lafayette Benedict Mendel, biochemist, was born February 5, 1872, in Delhi, New York, the son of German immigrants. Lafayette attended the local Delhi schools and was an outstanding student. At the age of 14 he took the entrance examination to Yale in Latin, Greek, and mathematics and in 1887 he entered the university as the youngest member of his class. At Yale Mendel continued his academic success while studying economics, the classics, the humanities in general. He graduated with Phi Beta Kappa standing in 1891. Although during his undergraduate years Mendel had shown little interest in the physical and biological sciences, he decided to enter the Sheffield Scientific School to pursue graduate study in chemistry with the thought of later becoming a doctor. As a graduate student Mendel's studies so fascinated him that he gave up the idea of studying medicine and decided instead to pursue a career in physiological chemistry, as biochemistry was then called.

Mendel received his Ph.D. degree from Yale in 1893. On the strength of the publication of his Ph.D. thesis in an English journal and his graduate school record, he was appointed an assistant to Russell H. Chittenden in the Sheffield School's biochemistry laboratory. With the exception of a year of study in Europe in 1895-96, Yale remained Mendel's academic home for the rest of his life. In 1897 he advanced to the position of assistant professor and in 1903 reached the rank of full professor of biochemistry. In 1921 he was made Sterling Professor of Physiological Chemistry, a position he held for the rest of his life. In addition to research and teaching Mendel also served on the governing boards of Yale's graduate school, the library, and the schools of medicine and science. He died in New Haven of heart disease on December 9, 1935. Shortly after Mendel died in 1935, memorial exercises were held at Yale to honor his memory. Looking back on Mendel's career, Phoebus A. T. Levene, the distinguished physiologist and chemist, said, At the beginning of Professor Mendel's career the term 'balance' stood for the daily requirement of the number of calories in the fats, of carbohydrates, and of proteins. It was little realized that in each of these categories of foodstuffs there were present individual substances possessing different values. To connect these values with chemical structure was to the clear vision of Professor Mendel the task of a new science of nutrition.

When Mendel began his career in biochemistry in 1893, little was known of the chemical composition of the various constituents of food. Still less was known about how these constituents affected the body's chemistry. From approximately 1896 to 1909 Mendel combined his knowledge of physiology and chemistry in the elucidation of biological functions through

chemical means. During this period he published numerous papers dealing with digestion and the absorption of proteins. He also investigated the pathways of excretion of certain inorganic salts, the composition and chemical activity of embryonic tissues, and the biochemical significance of muscle extractives. His research in these years led Mendel to the conclusion that there was a strong relationship between the chemical constitution of food proteins and their nutritive value to the body.

He was also convinced that there were other unknown substances in food which were of vital importance to the nutritional process. Beginning in 1909 Mendel conducted joint research with Thomas B. Osborne of the Connecticut Agricultural Experimental Station. Together the two men investigated the nutritive value of proteins. Employing rats as test animals they soon discovered that something in whole milk is essential both for biological maintenance and growth. In 1913 they divided these unknown substances in milk into two basic groups, one of which was soluable in water (vitamin B) and the other soluable in fat (vitamin A). By carefully controlling the quantity of these substances fed to the rats, they were able to produce biological effects in the test animals. Their conclusion was that these substances, vitamins A and B, were necessary to promote maintenance and growth and that their absence could lead to disease. They also discovered that other foods such as cod liver oil contained the vitamins and could be used as a substitute for milk. In later years more vitamins were identified and eventually their chemical composition was unraveled. Mendel and Osborne were pioneers on the path to a full explanation of the role of vitamins in the body's complex Chemistry.

In later years Mendel and Osborne turned their attention to the study of amino acids in proteins. In paper after paper they outlined the nutritive value of different proteins and demonstrated that the quantitative and qualitative differences in the content of amino acids in various proteins had definite biological implications. According to Henry C. Sherman writing in 1936 in Science, "Their experimental correlation of the amino acid constitutions of different proteins with the functions and efficiencies of these proteins in nutrition will long remain one of the outstanding landmarks in either a chemical or physiological survey of modern science." The practical results of the Mendel's research on proteins was that the nutritional value of various foods was dependent on knowledge of their proteins, or, more simply, all foods are not protein equal.

Because of his contributions to the knowledge of vitamins and protein Mendel became widely known as an expert in nutrition. He served for years as an advisor to the Department of Agriculture. During World War I he aided the Food Administration in determining the nutritive value of essential foods that were shipped to the Allied armies. He was also very active in the professional societies. He served as president of the American Physiological Society of Biological Chemists, and the American Institute of Nutrition. His public prestige was large. He advised the food industry on questions of nutrition and was widely respected and heeded by practicing physicians. Mendel published over 300 research papers and authored two books, Changes in the Food Supply and Their Relation to Nutrition (1916) and Nutrition, the Chemistry of Life (1923).

The significance of Lafayette B. Mendel was that he contributed to placing the study of nutrition on a truly scientific basis. Although today the results of his research may seem primitive, he did ask the questions which have long guided the study of food and its relation to the body's chemistry. The pure science results of his research were new knowledge of biochemistry. The practical results were that Americans learned better dietary habits and these habits contributed to a decrease in illnesses, to greater life  expectancy, and to better health among the general population.

Click here for the National Register of Historic Places nomination file.