INSECT POWDER GS 
chlorids. They made no tests as to the insecticidal action of these 
substances, but they are probably inert. 
Siedler (258), 1915, distilled 30 kilograms of half-closed flowers 
with dry steam, extracted the distillate with ether, and thus obtained 
a salvelike mass of strong characteristic odor. The yield was 20.212 
grams, or 0.067 per cent of the original material. Spread on un- 
glazed porcelain, all was absorbed but 0.789 gram. By fractional 
recrystallization from aqueous alcohol two bodies were obtained from 
this unabsorbed portion: (1) Fine needles, melting point 54-56° C.; 
and (2) fine plates, melting point 58-60°. Recrystallized from 
absolute alcohol this substance had a melting point of 62°. Ele- 
mentary analysis of (1) showed it to correspond closely to the formula 
CyH3. Analysis of (2) showed a formula approximating palmitic 
acid. The material absorbed by the porous plate was extracted with 
ether, and this concentrated solution mixed with 2 parts ether and 
1 part alcohol. By extraction with sodium bisulphite solution, 0.049 
gram of material was obtained of an aromatic odor, but without 
effect upon insects. By extraction with 2 per cent potassium hydroxid 
solution, 3.156 grams of material was isolated. No test for phenol 
could be obtained. An acid of butyric odor was obtained, but it 
was inert toward insects. Other tests, such as distillation of the 
material under reduced pressure, are recorded by Siedler, but nothing 
possessing insecticidal action could be isolated. 
Kvidently, then, a number of investigations on the nature of the 
active insecticidal principle of Pyrethrum had been carried out 
before 1916, but the results vary greatly. Table 47 gives a brief 
summary of these results. 
TABLE 47.—Summary of investigations on active insecticidal principle of Pyrethrum, 
1854 to 1915 
| 
Bibliog- | Speci : er : 
: ecies of Pyrethrum Active principle considered 
Year Investigator raphy P 
reference | used to be— 
1854 | Ragazzini (de Visiani) ---- 67 | Cinerarizfoliwm____----_- A mixture of substances, nature 
not determined. 
1863 | Heller & Kletzinsky 14S RosewmN Gs =2 FS Se re eS An essential oil and santonin. 
(Hanamann). pie A ora: 
1863 | Hanamann_-_-_-____-------- 118, eee domseehs SETS S 2 | An essential oil, “‘persicin. 
eovorisounenrs ee) = 22 le ee fP284- Osha C2) hao peek en 2 ee ee dove : 
1876 | De Bellesme_------------- Sy Co) ee age ee A “crystallized principle. 
WSivaesemenon.. 2-5 2-2 =.= 253) i eResewm: Gb) 435-2. ht 4 An essential oil. 
Heise Phare se wee tee 111 | Rosewm and Carneuwm | A resin ahd an amin. 
[AVC RED GL SST ee ae ene 60 | (2) eer Vp rye A free volatile acid. 
Hee OX COR So ee ZA) Ss Bae Se ee A soft resin. 
PRO u ee uleties: = wot Sake | OG |. Cet ete Te EP ESSE Se Soluble in ether. 
1889- 296, 297 > Isolated a paraffin, a phytosterol, 
ie » <¥(> |S Cinerarizfolium__..-----|; an alkaloid, and a glucoside, 
1894 jZsc0 Supe SS: { 298, 299 } but all were inert. 
1890 | Hirschsohn—=--==---.---=-- 133;4|aesewmny Gi) ss Ae 8 Not acid and not volatile. 
18908) “Wrymaard j=. 2-22 — -2--- =. is) yee es ee Principally a resin. 
1890 | Schlagdenhauffen and 245 | Cinerarizfolium--_-_---_-- ““Pyrethrotoxic acid.”’ 
Reeb. ea: 
OG Mahms: cesses Sa TA TIN eee Ot ts = 22 ntt ) eae: An essential oil. 
TSOps ese OIsse ses as = oe 642122 C02 Se A resin. ; ; 
eG 7ol- Durrania = 2 -5)==——-——5- = (Ail see GOs. ims oS A resin and volatile oil. 
WRORE{ GerakGee= t= oS OS }eses— 2 (0 feat See fee Eee An oleoresin and volatile oil. 
1905 STL ae ee PEG 237s dots---=2: epee _| A sirupy- resin; “‘pyretol:” 
aoe iarhanls ee SOA 5 = 6 (0 ae ane Sa ce An ester, “‘pyrethron.”’ 
1909 | Reeb aio ee ae PAY: eS GO) SR ee ees “‘Pyrethrotoxic acid.” _ 
1912 Yoshimura and Trier____- 205) 8 8 (3 (0) 2 eres Bre § SR TS Cholin and stachydrin (inert). 
fO5: SleGgleps = sees) a kats DAS: a ee othe ee ap eee Nothing definite. 
70572°—26—_5 
