The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
Estimated average burden
hours per response: 23.8
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
3M CO. COM 88579Y101 3,298 18,692 SH   SOLE   0 0 18,692
ABBOTT LABORATORIES COM 002824100 8,067 92,878 SH   SOLE   0 0 92,878
ABBVIE INC COM 00287Y109 1,627 18,371 SH   SOLE   0 0 18,371
ADOBE SYSTEMS INCORPORATED COM 00724F101 4,823 14,623 SH   SOLE   0 0 14,623
AIR PRODUCTS & CHEMICALS COM 009158106 321 1,368 SH   SOLE   0 0 1,368
ALLSTATE CORPORATION COM 020002101 729 6,483 SH   SOLE   0 0 6,483
ALPHABET INC NON-VOTING CL C COM 02079K107 8,653 6,472 SH   SOLE   0 0 6,472
ALPHABET INC VOTING CL A COM 02079K305 656 490 SH   SOLE   0 0 490
ALTRIA GROUP COM 02209S103 227 4,556 SH   SOLE   0 0 4,556
AMAZON.COM INC COM 023135106 8,238 4,458 SH   SOLE   0 0 4,458
AMERICAN ELECTRIC POWER COM 025537101 246 2,606 SH   SOLE   0 0 2,606
AMERICAN EXPRESS INC COM 025816109 3,477 27,930 SH   SOLE   0 0 27,930
AMGEN INC COM 031162100 1,195 4,958 SH   SOLE   0 0 4,958
APPLE INC COM 037833100 12,792 43,562 SH   SOLE   0 0 43,562
AQUA AMERICA COM 03836W103 7,730 164,672 SH   SOLE   0 0 164,672
ARCHER DANIELS MIDLAND CO COM 039483102 1,153 24,876 SH   SOLE   0 0 24,876
AT&T CORP NEW COM 00206R102 2,393 61,229 SH   SOLE   0 0 61,229
ATMOS ENERGY CORP COM 049560105 2,033 18,175 SH   SOLE   0 0 18,175
BALL CORP COM 058498106 252 3,900 SH   SOLE   0 0 3,900
BANK OF AMERICA COM 060505104 1,455 41,317 SH   SOLE   0 0 41,317
BANK OF NEW YORK MELLON CORP COM 064058100 969 19,254 SH   SOLE   0 0 19,254
BECTON DICKINSON COM 075887109 11,689 42,980 SH   SOLE   0 0 42,980
BERKSHIRE HATHAWAY INC DEL CLA COM 084670108 4,415 13 SH   SOLE   0 0 13
BERKSHIRE HATHAWAY INC DEL CLA COM 084670702 795 3,510 SH   SOLE   0 0 3,510
BOEING COM 097023105 3,143 9,648 SH   SOLE   0 0 9,648
BP PLC SPONS ADR COM 055622104 262 6,945 SH   SOLE   0 0 6,945
BRISTOL-MYERS SQUIBB COMPANY COM 110122108 1,028 16,019 SH   SOLE   0 0 16,019
C S X CORPORATION COM 126408103 507 7,000 SH   SOLE   0 0 7,000
CABLE ONE INC COM 12685J105 561 377 SH   SOLE   0 0 377
CATERPILLAR INCORPORATED COM 149123101 5,384 36,456 SH   SOLE   0 0 36,456
CHEMOURS CO COM 163851108 12,715 702,885 SH   SOLE   0 0 702,885
CHEVRON CORP COM 166764100 6,968 57,824 SH   SOLE   0 0 57,824
CHURCH & DWIGHT CO INC COM 171340102 10,599 150,678 SH   SOLE   0 0 150,678
CISCO SYSTEMS INC COM 17275R102 6,880 143,447 SH   SOLE   0 0 143,447
COASTAL CARIBBEAN OILS & MINER COM 190432203 0 69,910 SH   SOLE   0 0 69,910
COCA-COLA COMPANY COM 191216100 2,318 41,882 SH   SOLE   0 0 41,882
COLGATE-PALMOLIVE COMPANY COM 194162103 430 6,252 SH   SOLE   0 0 6,252
COMCAST CORP NEW CL A COM 20030N101 280 6,222 SH   SOLE   0 0 6,222
CONOCOPHILLIPS COM 20825C104 360 5,534 SH   SOLE   0 0 5,534
CORNING INC. COM 219350105 707 24,300 SH   SOLE   0 0 24,300
CORTEVA INC COM 22052L104 31,513 1,066,079 SH   SOLE   0 0 1,066,079
CVS CAREMARK CORPORATION COM 126650100 591 7,950 SH   SOLE   0 0 7,950
DANAHER CORP COM 235851102 648 4,225 SH   SOLE   0 0 4,225
DEERE AND CO. COM 244199105 217 1,250 SH   SOLE   0 0 1,250
DENTSPLY SIRONA INC COM 24906P109 2,262 39,965 SH   SOLE   0 0 39,965
DISCOVER FINANCIAL SERVICES COM 254709108 508 5,992 SH   SOLE   0 0 5,992
DOMINION RESOURCES INC OF VA COM 25746U109 4,644 56,072 SH   SOLE   0 0 56,072
DOVER CORPORATION COM 260003108 263 2,285 SH   SOLE   0 0 2,285
DOW CHEMICAL COMPANY (THE) COM 260543103 60,358 1,102,840 SH   SOLE   0 0 1,102,840
DTE ENERGY COM 233331107 391 3,011 SH   SOLE   0 0 3,011
DU PONT (E.I.) DE NEMOURS & CO COM 263534109 70,896 1,104,297 SH   SOLE   0 0 1,104,297
DUKE ENERGY CORP COM 26441C204 1,512 16,577 SH   SOLE   0 0 16,577
ELI LILLY & CO COM 532457108 635 4,833 SH   SOLE   0 0 4,833
EMERSON ELECTRIC CO. COM 291011104 1,083 14,206 SH   SOLE   0 0 14,206
ENBRIDGE INC. COM 29250N105 1,045 26,267 SH   SOLE   0 0 26,267
EXELON CORP COM 30161N101 225 4,936 SH   SOLE   0 0 4,936
EXXON MOBIL CORPORATION COM 30231G102 10,346 148,272 SH   SOLE   0 0 148,272
FEDERAL REALTY INV TR S B I COM 313747206 1,464 11,374 SH   SOLE   0 0 11,374
FEDEX CORP COM 31428X106 4,423 29,248 SH   SOLE   0 0 29,248
FISERV INC COM 337738108 357 3,090 SH   SOLE   0 0 3,090
FORTIVE CORP COM 34959J108 343 4,488 SH   SOLE   0 0 4,488
FRANKLIN RESOURCES INC COM 354613101 587 22,585 SH   SOLE   0 0 22,585
GENERAL ELECTRIC COMPANY COM 369604103 2,129 190,793 SH   SOLE   0 0 190,793
GENERAL MILLS INC COM 370334104 729 13,614 SH   SOLE   0 0 13,614
GRAHAM HOLDINGS CO. COM 384637104 215 336 SH   SOLE   0 0 336
HEALTH PEAK PROPERTIES INC COM 42250P103 259 7,524 SH   SOLE   0 0 7,524
HERSHEY COMPANY COM 427866108 1,732 11,787 SH   SOLE   0 0 11,787
HOME DEPOT COM 437076102 1,068 4,891 SH   SOLE   0 0 4,891
HONEYWELL INTERNATIONAL INC COM 438516106 3,218 18,182 SH   SOLE   0 0 18,182
ILLINOIS TOOL WORKS INC. COM 452308109 11,579 64,459 SH   SOLE   0 0 64,459
INTEL CORP COM COM 458140100 7,919 132,309 SH   SOLE   0 0 132,309
INTERNATIONAL BUSINESS MACHINE COM 459200101 2,644 19,724 SH   SOLE   0 0 19,724
INTERNATIONAL PAPER CO COM 460146103 263 5,709 SH   SOLE   0 0 5,709
INTUIT INC COM 461202103 943 3,600 SH   SOLE   0 0 3,600
ISHARES MSCI EAFE INDEX COM 464287465 377 5,434 SH   SOLE   0 0 5,434
ISHARES NASDAQ BIOTECH INDEX COM 464287556 6,605 54,811 SH   SOLE   0 0 54,811
ISHARES RUSSELL 2000 IDX COM 464287655 5,087 30,705 SH   SOLE   0 0 30,705
ISHARES RUSSELL MIDCAP INDEX COM 464287499 7,100 119,083 SH   SOLE   0 0 119,083
JOHNSON & JOHNSON COM 478160104 15,694 107,586 SH   SOLE   0 0 107,586
JPMORGAN CHASE & CO. COM 46625H100 13,166 94,449 SH   SOLE   0 0 94,449
KELLOGG COMPANY COM 487836108 2,807 40,586 SH   SOLE   0 0 40,586
KIMBERLY-CLARK CORP COM 494368103 2,837 20,625 SH   SOLE   0 0 20,625
LABORATORY CORP OF AMERICA COM 50540R409 1,048 6,197 SH   SOLE   0 0 6,197
LINDE PLC COM G5494J103 385 1,807 SH   SOLE   0 0 1,807
LOCKHEED MARTIN COM 539830109 939 2,412 SH   SOLE   0 0 2,412
LOWES COS COM 548661107 12,638 105,524 SH   SOLE   0 0 105,524
M & T BANK CORP COM 55261F104 2,300 13,550 SH   SOLE   0 0 13,550
MANPOWER INC WISCONSIN COM 56418H100 459 4,724 SH   SOLE   0 0 4,724
MARRIOTT INTERNATIONAL, NEW IN COM 571903202 8,242 54,431 SH   SOLE   0 0 54,431
MARRIOTT VACATIONS WORLDWIDE C COM 57164Y107 225 1,745 SH   SOLE   0 0 1,745
MC DONALD'S CORPORATION COM 580135101 11,313 57,249 SH   SOLE   0 0 57,249
MEDTRONIC INC COM G5960L103 505 4,452 SH   SOLE   0 0 4,452
MERCK & COMPANY INCORPORATED N COM 58933Y105 6,798 74,743 SH   SOLE   0 0 74,743
MICROSOFT CORPORATION COM 594918104 19,834 125,773 SH   SOLE   0 0 125,773
MONDELEZ INTL INC COM 609207105 264 4,797 SH   SOLE   0 0 4,797
MORGAN STANLEY & CO COM 617446448 618 12,088 SH   SOLE   0 0 12,088
MOTOROLA SOLUTIONS, INC COM 620076307 819 5,084 SH   SOLE   0 0 5,084
NESTLE SA REG ADR COM 641069406 249 2,303 SH   SOLE   0 0 2,303
NEXTERA ENERGY COM 65339F101 5,353 22,105 SH   SOLE   0 0 22,105
NORFOLK SOUTHERN CORP COM 655844108 297 1,531 SH   SOLE   0 0 1,531
NORTHERN TRUST CORP COM 665859104 1,105 10,400 SH   SOLE   0 0 10,400
ORACLE CORP COM 68389X105 421 7,949 SH   SOLE   0 0 7,949
PEPSICO INCORPORATED COM 713448108 12,680 92,781 SH   SOLE   0 0 92,781
PFIZER INCORPORATED COM 717081103 1,470 37,522 SH   SOLE   0 0 37,522
PHILIP MORRIS INTERNATIONAL COM 718172109 423 4,968 SH   SOLE   0 0 4,968
PHILLIPS 66 COM 718546104 517 4,638 SH   SOLE   0 0 4,638
PIONEER NAT RES CO COM 723787107 227 1,500 SH   SOLE   0 0 1,500
PNC FINANCIAL SERVICES GROUP COM 693475105 584 3,656 SH   SOLE   0 0 3,656
POWERSHARES QQQ TR ETF SERIES COM 73935A104 1,321 6,211 SH   SOLE   0 0 6,211
PROCTER & GAMBLE COMPANY COM 742718109 16,248 130,089 SH   SOLE   0 0 130,089
PUBLIC SERVICE ENTERPRISE GROU COM 744573106 265 4,490 SH   SOLE   0 0 4,490
RAYTHEON COMPANY NEW COM 755111507 242 1,100 SH   SOLE   0 0 1,100
SAUL CENTERS INC. COM 804395101 368 6,978 SH   SOLE   0 0 6,978
SELECT SECTOR SPDR TR UTILITIE COM 81369Y886 291 4,500 SH   SOLE   0 0 4,500
SMUCKER J.M. CO COM 832696405 521 5,006 SH   SOLE   0 0 5,006
SOUTHERN COMPANY (THE) COM 842587107 3,294 51,717 SH   SOLE   0 0 51,717
SPDR S&P 500 ETF COM 78462F103 363 1,128 SH   SOLE   0 0 1,128
SYSCO CORPORATION COM 871829107 1,511 17,667 SH   SOLE   0 0 17,667
T ROWE PRICE GROUP INC. COM 74144T108 12,114 99,429 SH   SOLE   0 0 99,429
TARGET CORP COM 87612E106 710 5,534 SH   SOLE   0 0 5,534
TEXAS INSTRUMENTS COM 882508104 840 6,548 SH   SOLE   0 0 6,548
THE TJX COMPANIES COM 872540109 244 4,000 SH   SOLE   0 0 4,000
THE TRAVELERS COS INC COM 89417E109 565 4,127 SH   SOLE   0 0 4,127
THERMO FISHER SCIENTIFIC COM 883556102 491 1,510 SH   SOLE   0 0 1,510
UDR INC COM 902653104 960 20,549 SH   SOLE   0 0 20,549
UNILEVER COM 904784709 276 4,800 SH   SOLE   0 0 4,800
UNION PACIFIC CORP COM 907818108 6,532 36,128 SH   SOLE   0 0 36,128
UNITED HEALTHCARE CORP COM 91324P102 7,138 24,281 SH   SOLE   0 0 24,281
UNITED TECHNOLOGIES CORP COM COM 913017109 8,844 59,053 SH   SOLE   0 0 59,053
US BANCORP DEL (NEW) COM 902973304 272 4,585 SH   SOLE   0 0 4,585
VANGUARD EMERGING MARKETS ETF COM 922042858 778 17,499 SH   SOLE   0 0 17,499
VANGUARD FTSE DEVELOPED MARKET COM 921943858 1,179 26,749 SH   SOLE   0 0 26,749
VANGUARD INFORMATION TECHNOLOG COM 92204A702 51,130 208,823 SH   SOLE   0 0 208,823
VANGUARD MID CAP ETF COM 922908629 6,157 34,554 SH   SOLE   0 0 34,554
VANGUARD REIT ETF COM 922908553 660 7,110 SH   SOLE   0 0 7,110
VANGUARD S&P ETF COM 922908363 991 3,350 SH   SOLE   0 0 3,350
VANGUARD SMALL CAP ETF COM 922908751 4,575 27,618 SH   SOLE   0 0 27,618
VANGUARD TOTAL STOCK MARKET COM 922908769 3,034 18,541 SH   SOLE   0 0 18,541
VERIZON COMMUNICATIONS COM 92343V104 4,500 73,293 SH   SOLE   0 0 73,293
VISA INC CLASS A COM 92826C839 12,240 65,139 SH   SOLE   0 0 65,139
VULCAN MATERIALS CO COM 929160109 346 2,400 SH   SOLE   0 0 2,400
WAL-MART STORES INC COM 931142103 593 4,987 SH   SOLE   0 0 4,987
WALGREENS BOOTS ALLIANCE, INC. COM 931427108 3,852 65,335 SH   SOLE   0 0 65,335
WALT DISNEY COMPANY COM 254687106 9,256 63,997 SH   SOLE   0 0 63,997
WASH REAL ESTATE INV TRUST S B COM 939653101 2,476 84,855 SH   SOLE   0 0 84,855
WASTE CONNECTIONS INC COM 94106B101 300 3,300 SH   SOLE   0 0 3,300
WEINGARTEN REALTY INVS S B I COM 948741103 2,423 77,557 SH   SOLE   0 0 77,557
WELLS FARGO & CO. NEW COM 949746101 5,961 110,801 SH   SOLE   0 0 110,801
WEYERHAEUSER CO COM 962166104 318 10,539 SH   SOLE   0 0 10,539
WHITE MOUNTAINS INS. COM G9618E107 222 199 SH   SOLE   0 0 199
ZIMMER BIOMET HOLDINGS INC. COM 98956P102 500 3,340 SH   SOLE   0 0 3,340