In studying Kayser Etude Number 30 (International Music Company No. 3078) the bow hand and the left hand must work together to create a “spun” effect. Slurs of 18 notes are difficult in the beginning, so you may practice with slurring only three notes, then six, then nine, etc. There are two different kinds of left hand patterns. The first is trips with upper neighbors that return to the original note. The second is the arpeggiation that moves up and down on different chords.
The triplets with upper neighbor tones should be practiced only playing the first of each of the three to isolate the melodic pattern. Then each triplet group can be played with “grace notes” using the upper neighbor and returning to the original note. Finally, even triplets the place an emphasis on the first note of the three will allow the passage to flow, revealing the melodic line.
The arpeggio section requires a more analysis to isolate the melodic structure. The middle note of each group of three can be left out to find the notes that trace the melodic line. It becomes a sort “jig” feel if you play it in the fashion. Eventually, the middle notes should be added back in and practiced with floating fermatas to solidify notes. Adding three note slurs should then be done, eventually to six note slurs, etc. I find this section to be very tricky both for the left and right hands.
You can look to the Internet Music Library Project to find a Schirmer edition of the 36 Studies by Kayser.