A FRIEND once told me he kept his circulatory system strong by alternately smoking cigars and drinking martinis -- the capillaries contracted by the nicotine, then expanded by the alcohol to create a healthy flexing effect. Reading through the series of essays, poems and letters about Ross Macdonald/Kenneth Millar which make up Inward Journey: Ross Macdonald (Cordelia Editions, $25) had the same sort of alternating effect on my temper. Downers follow uppers, disappointment replaces delight.

Ralph P. Sipper, one of Ken Millar's Santa Barbara friends, edited and published the book and seems to have arranged his material for just such an effect. He opens with a 30-year-old lecture on detective fiction which Millar had read at the University of Michigan about the time his Ross Macdonald pen name was gaining a national following. This piece, Millar in the role of critic and scholar, is better than the usual scholarly criticism, but that's faint praise. It's only lasting interest will be to bona fide Macdonald fans curious about how Millar's mind was working at that stage of his development. This example of Millar pedantic is followed by Millar enraged -- a 1952 letter to Alfred A. Knopf answering a request that Millar revise a book to make it sound more like Raymond Chandler. It's wonderful prose, revealing the author's skill, his indignation and his literary intentions. So it goes in Inward Journey -- something fine, followed by something dull.

The high point for me is a brief piece in which John D., the original MacDonald mystery writer, reports how he learned Millar had appropriated his name as a nom de plume and, later, how Cosmopolitan magazine used the new John MacDonald as a cheaper way to attract readers. It is 1959. John D. is living cheap in Mexico, eking it out on short story sales to the mystery pulps and various slick magazines. A letter arrives from Mom back in Ithaca, N.Y. reporting that a friend had spotted his novel in a book store, the family has read it with great approval, and a dozen copies have been delivered to friends with a promise that he'll sign them on return to the United States. Why hadn't John told the family his book was being published? It's a good-natured account of what happened next with just a tinge of residual resentment visible between the lines. John D.'s tolerance of this outrage should earn him some sort of Turn-The-Other Cheek award.

Among the other ups amid the downs in this slim volume: Margaret Millar tells us in a lovely little vignette how she met her husband- to-be. Historical novelist Robert Easton recalls how Millar's tragic childhood influenced the story of parental desertion he told us in so many of his books. Novelist-collector George Sims reminds all of us Ross Macdonald fans why we are happy to read the same plot so often. He gives us a sampler of those dazzling metaphors in which Lew Archer described the sorrowful world and its doom-struck inhabitants. Diane Wakoski awards Lew Archer the Lythrum Salicaria Author's Prize in a touching little poem.

Some of the 25 contributors knew Millar only casually, or briefly. British crime writer/critic Julian Symons extracts from such a relationship details which illuminate Millar's unusual personality. Otto Penzler recounts the happy chance which led to republication of Millar's short stories. Both men do it fast in graceful little essays. Others were less merciful. Sipper includes two or three turgid, pretentious literary critiques. Whether or not it was the editor's intention, these tend to demonstrate that even at his worst Millar couldn't sound as pompous as the standards of academic writing seem to demand.

MACDONALD fans can also exercise their nostalgia in the newest offering of Michael Z. Lewin, n just becaue his private detective Albert Samson seems an older, seedier and less sophisticated Lew Archer, but because the plot of Out of Season (Morrow, $12.95) looks at first like a more complex version of the one Millar used so often.

Samson, his private eye business dried up by the civilizing of Indiana's divorce laws, is visited by an Indianapolis banker whose wife has just learned her birth certificate is a forgery. Her "mother," now drifting into senility in a nursing home, had given it to her. Tracing down the woman's identity leads Samson into much of the sort of familial confusion that was grist for the Macdonald mill. But Macdonald followers who want to switch loyalties will find Lewin devises more intricate plots and peoples them with more interesting characters. They'll miss Lew Archer's habit of thinking in metaphor, which give the Macdonald books a sort of bleak, pessimistic poetry. On the other hand, they're going to enjoy Lewin's way of giving even the most minor of characters vivid and unstereotyped personalities. (For example, a strip joint owner who looks mean and tough turns out to be one of the nicest guys in Indianapolis.)

A word of caution: Avoid the dust jacket text. It gives away some of the plot. Editors who commit that sin should be condemned to read the complete works of James Fenimore Cooper.

Lewin is a Harvard honors graduate in physics with an Edgar scroll to his credit and enough confidence in his skill to need neither the crotch-groping sex scenes or the descriptions of bloody violence which mark the work of less confident practitioners. For example, Tom Topor begins Coda (Scribners, $13.95) with his hero awakening in the sack with a young woman. She asks if he will do her a favor.

"She was ten years younger than me and as tireless as a beaver building a dam, so I immediately got a picture of some acrobatic marathon, a decathlon of lust that would twist me into a pretzel and send me quivering to the coronary-care unit at New York Hospital. 'Ummmmm,' I said slowly."

It's hard to take a book seriously after a start like that. (Remember how artfully Hammett handled the same thing in The Maltese Falcon?) But I did read on to see if it gets better. It does, involving an intriguing plot idea about a hunt for a musician who survived from a concentration camp orchestra. Topor writes with skill and is so expert with dialogue that I was ready to tolerate his smart-aleck protagonist. But then I ran into a description of a Nazi beating a mother and infant to death with a club until nothing remained but the proverbial bloody puddle, and a teen-aged pigeon keeper getting his face pounded in with a pistol. Well, a lot of readers will like it.

IF YOU WANT to see crotch-grabbing (of a somewhat different sort) and throat-cutting raised to art by a top-flight writer, try All the Pretty People (St. Martin's, $14.95) by Jack S. Scott. It opens with Detective Inspector Alfred Stanley Rosher, rain pouring from the brim of his fedora, engaged in dialogue with a naked young man who believes he is God and intends to prove it by jumping off a building. Rosher prevents this suicide with a steely grip on the jumper's private parts. As Scott assures us, "a sharply squeezed testicle will divert a veritable saint from his ecstacy." The neurotic young man is instantly subdued. Rarely has the reason for such a surrender been more believably motivated.

The "pretty people" in this one are involved in drugs and bloody murder and the comedy is strung along a well-tuned mystery. But the plot is beside the point. The fun is watching Rosher, the most uncouth detective in Christendom, floundering his way toward the solution. For those who haven't met the man in Scott's earlier books, here he is on the doorstep of a couple he's come to question:

"Inspector Rosher, encased in his durable blue serge suit with double seat and the reinforced cuffs, the like of which is not made anymore, widened the smile, but not so far as was his wont when a ring on a door brought forth a lady. The full, brown-toothed beam he reserved for the female public, who also merited snatching off the black hat and its gripping between hairy hands, in front of the barrel chest. This man was not female. The hat remained untouched . . ."

The novel bears the imprint of Joan Kahn, a giant among editors. It guarantees that the writer has had his feet held to the fire and the book is just as good as Scott could make it.

THE LATEST adventures of a totally different cop, Sgt. Norah Mulcahaney of the NYPD are available in Lillian O'Donnell's Lady Killer (Putnam, $14.95.). This one puts Norah on the trail of what first seems to be another serial killer, one who cuts the throats of young women. Halfway through it dawns upon the experienced mystery reader that he may be involved in yet another variation of the old ABC murder plot, in which only one murder has a reason and the others are used to camouflage it. However, Norah gets the same idea at about the same time, which is way too early for the mystery to be solved. So you must be wrong. You are, more or less, and I freely confess that I didn't have the foggiest idea who the bad guy was until O'Donnell showed me in another of her fine, cliffhanging finishes.

O'Donnell has beeen at it for a quarter century (after becoming Broadway's first woman stage director back in 1940) and her plots are dazzling. Here she shifts viewpoint between Norah and that of a mean kid with a sharp knife. It keeps the reader both informed and confused. Sgt. Mulcahaney's cynicism about the average New York citizen bothers me some, but then such an attitude exactly fits the character of Sgt. Mulcahaney and I must admit I'm more naive about such matters than most.