I’d be very worried if I whizzed anything past No. 4.
From what I can tell, Dr. Julius Vogel of Germany (not to be confused with Sir Julius Vogel of New Zealand) was instrumental in detecting disease and other maladies by analyzing urine samples in the mid to late 1800s and writing treatises about it and other studies involving the endocrine system. And yes, he wrote about “asparagus pee.” It’s because of Dr. Vogel that your doctor asks you to piss in a cup.
You can read an entire 1876 Treatise by Dr. William Roberts M.D. on urine color diagnoses that features the work of Dr. Vogel here.
[Image with link found here.]