(Update, 19th April 2021.)
We lost Samwise earlier this month, to lymphoma, probably by everybody’s assessment, including veterinarians, due to exposure to herbicides, insecticides, and pesticides earlier in his life. He was a noble, and wonderful cat. He was smart. He could open doors having door knobs. He could open big drawers under our platform bed, climb in, and close them behind him. He loved knocking pens off of desks. And he hunted, but captured things gently and alive, and always released them. Sure, he might have wanted them to run to chase them again.
But there was a deep soul there. And his death is a statement of how random and arbitrary life is in this universe. I do not believe in a God because if She existed, she would have to be judged psychotic. Ergo, She doesn’t exist. It’s nothing but the sound of random Hydrogen atoms.

I miss him deeply. He was my friend. He was companion while I worked hours at my computer, patient and loving. And he would convince me to accompany him out on adventures on our property, which I also so deeply miss.

So, in his memory, with love and hurt and gratitude, I offer Larkin Poe doing Pink Floyd‘s “Wish You Were Here”.
References to scientific and veterinary literature on lymphoma in cats and dogs:
Gavazza, Alessandra, Silvano Presciuttini, Roberto Barale, George Lubas, and Biancaurora Gugliucci. "Association between canine malignant lymphoma, living in industrial areas, and use of chemicals by dog owners." Journal of Veterinary Internal Medicine 15, no. 3 (2001): 190-195.
Takashima-Uebelhoer, Biki B., Lisa G. Barber, Sofija E. Zagarins, Elizabeth Procter-Gray, Audra L. Gollenberg, Antony S. Moore, and Elizabeth R. Bertone-Johnson. "Household chemical exposures and the risk of canine malignant lymphoma, a model for human non-Hodgkin’s lymphoma." Environmental Research 112 (2012): 171-176.
Tranah, Gregory J., Paige M. Bracci, and Elizabeth A. Holly. "Domestic and farm-animal exposures and risk of non-Hodgkin's lymphoma in a population-based study in the San Francisco Bay Area." Cancer Epidemiology and Prevention Biomarkers 17, no. 9 (2008): 2382-2387.
Reif, John S. "Animal sentinels for environmental and public health." Public Health Reports 126, no. 1_suppl (2011): 50-57.
Deziel, Nicole C., Mary H. Ward, Erin M. Bell, Todd P. Whitehead, Robert B. Gunier, Melissa C. Friesen, and John R. Nuckols. "Temporal variability of pesticide concentrations in homes and implications for attenuation bias in epidemiologic studies." Environmental health perspectives 121, no. 5 (2013): 565-571.
Poppenga, Robert H., and Frederick W. Oehme. "Pesticide use and associated morbidity and mortality in veterinary medicine." In Hayes' Handbook of Pesticide Toxicology, pp. 285-301. Academic Press, 2010.
Pimentel, David, Anthony Greiner, and Tad Bashore. "Economic and environmental costs of pesticide use." Environmental toxicology: current developments (1998): 121-151.
Sorry to hear about your loss. My kitty friend of many years died a year ago, and I still miss him. I have a ‘replacement’ now (not that a friend can ever be truly replaced), another kitten, and he’s helping to ease my pain. Good choice of music there to see your friend off. Here’s to Samwise!